A national laboratory of the U.S. Department of Energy

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National Renewable Energy Laboratory 

Innovation for Our Energy Future 

Advanced Power Electronics 

Interfaces for Distributed Energy 

Workshop Summary 

August 24, 2006 

Sacramento, California 

B. Treanton and J. Palomo

California Energy Commission 

B. Kroposki and H. Thomas

National Renewable Energy Laboratory

Workshop Summary 

NREL/BK-581-40480 

October 2006 

NREL is operated by Midwest Research Institute ● Battelle Contract No. DE-AC36-99-GO10337 
Advanced Power Electronics 

Interfaces for Distributed Energy 

Workshop Summary 

August 24, 2006 

Sacramento, California 

B. Treanton and J. Palomo

California Energy Commission 

B. Kroposki and H. Thomas

National Renewable Energy Laboratory

Prepared under Task No. WW88.2005 

Workshop Summary 

NREL/BK-581-40480 

October 2006 

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Executive Summary 

The Advanced Power Electronics Interfaces for Distributed Energy Workshop, sponsored by 

the California Energy Commission Public Interest Energy Research (PIER) program and 

organized by the National Renewable Energy Laboratory, was held Aug. 24, 2006, in 

Sacramento, Calif. 

The workshop provided a forum for industry stakeholders to share their knowledge and 

experience about technologies, manufacturing approaches, markets, and issues in power 

electronics for a range of distributed energy resources. It focused on the development of 

advanced power electronic interfaces for distributed energy applications and included 

discussions of modular power electronics, component manufacturing, and power 

electronic applications. 

The workshop was organized into four sessions: 

• Experience With Modular Power Electronics 

• Advanced Concepts and Components 

• Modular Power Electronics 

• Power Electronics for Distributed Energy Applications. 

Each session included multiple presentations, and subsequent discussion periods allowed 

attendees to ask questions and share thoughts on power electronics issues. 

The presentation and discussion sessions revealed several themes: 

• The need for a standardized interface for power electronics 

• The importance of scalability in power electronics 

• The importance of modularity in power electronics 

• The need for power electronics to perform with high reliability and mean time 

between failure 

• The need to reduce the cost of power electronics components and address the 

increasing cost of current designs 

• The reluctance of industry to forfeit proprietary designs for a standardized interface 

and the threat/opportunity of commoditization 

• The need for longer warranties for power electronics products 

• The need for improved certification scenarios and lower-cost certification methods 

• The need to plan for power electronics early in system designs to reduce cost and 

increase effectiveness. 

• The recognition that power electronics interface manufacturing will compete in a 

global market. 

iv 
The information collected from this workshop is a resource for organizations that plan to 

submit proposals in response to an upcoming California Energy Commission PIER request 

for proposals for an advanced power electronic interface. 

Information about the workshop was posted on the California Energy Commission PIER 

Web site (see http://www.energy.ca.gov/pier/notices/2006-08-

24_workshop_power_elect.html). Forty-one people—representing industry, state and federal 

government, and national laboratories—attended. 

v 
Acronyms 

APEI Advanced Power Electronics Interface 

CBEMA Computer Business Equipment Manufacturers Association 

CPES Center for Power Electronics Systems 

DER distributed energy resources 

EPS electric power system 

ETO emitter turn-off 

IEEE Institute of Electrical and Electronics Engineers 

NREL National Renewable Energy Laboratory 

ONR Office of Naval Research 

PEBB Power Electronics Building Block 

PIER Public Interest Energy Research 

PV photovoltaics 

R&D research and development 

UL Underwriters Laboratories 

UPS uninterruptible power system 

vi 
Definitions 

Distributed energy resources (DER): DER are electric power sources located at or near the 

point of use or load center. DER include distributed generation, distributed energy storage, 

and demand response efforts. The energy generation resources include a range of 

technologies, such as photovoltaics, wind turbines, fuel cells, microturbines, combustion 

turbines, reciprocating engines, gas- and steam-powered turbines, Stirling engines, biomass 

systems, and solar thermal systems. Related systems and supporting technologies include 

integrated storage systems, power electronics, and control technologies. 

Plug and play: An approach in which hardware and software work together to automatically 

configure devices and assign resources. This allows hardware changes and additions without 

large-scale adjustments or modifications. The goal is to be able to plug in a new device and 

immediately use it, without complicated or significant setup modifications or adjustments. 

STATCOM: An abbreviation for “static compensator.” This device is a shunt-connected 

voltage controller typically used to limit reactive power fluctuations or harmonic content. It 

does not contain energy storage but can actively inject or draw reactive power. 

vii 
viii 
Table of Contents 

1 Introduction ..................................................................................................................................1

1.1 Workshop Sponsor............................................................................................... 1 

1.2 Workshop Structure ............................................................................................. 2

2 Workshop Introduction ...............................................................................................................3

2.1 “Power Electronics for Utility Applications at the Department of Energy,” 

Imre Gyuk, Department of Energy ...................................................................... 3 

2.2 “Power Electronics Research Assessment,” Forrest Small, Navigant................. 4 

2.3 Workshop Introduction Discussion...................................................................... 5

3 Session 1: Experience With Modular Power Electronics ........................................................6

3.1 “Power Electronic Building Blocks: Office of Naval Research Experience 

and Observations,” Terry Ericsen, Office of Naval Research ............................. 6 

3.2 “Integrated Power Electronics Building Block Modules, Converters, 

and Systems,” Fred Wang, Virginia Tech ........................................................... 7 

3.3 “Bricks and Buses,” Giri Venkataramanan, University of Wisconsin................. 8 

3.4 Session 1 Discussion............................................................................................ 9

4 Session 2: Advanced Concepts and Components.................................................................12

4.1 “Advanced Topologies for Distributed Energy Interface,” Ned Mohan, 

University of Minnesota .................................................................................... 12 

4.2 “Integrated Modules Simplify Systems Design,” John Mookken, 

SEMIKRON Inc................................................................................................. 12 

4.3 “Distributed Energy Advanced Power Electronic Interfaces,” Ben Kroposki, 

National Renewable Energy Laboratory............................................................ 13 

4.4 Session 2 Discussion.......................................................................................... 15

5 Session 3: Modular Power Electronics Distributed Energy Applications ...........................17

5.1 “Modular and Scalable Power Converters in the Uninterruptible Power 

Supply Industry,” Ian Wallace, Eaton................................................................ 17 

5.2 “Distributed Energy Applications Leverage High-Volume, Modular 

Power Converters,” Perry Schugart, American Semiconductor ........................ 18 

5.3 “Modular Inverters for Distributed Generation,” Matt Zolot, UQM................. 19 

5.4 Session 3 Discussion.......................................................................................... 20

6 Session 4: Power Electronics for Distributed Energy Applications.....................................21

6.1 “Power Electronics Conversion for Distributed Energy Applications,” 

Alex Levran, Magnetek Inc. .............................................................................. 21 

6.2 “Xantrex Power Electronics for Renewable Energy System Applications,” 

Ray Hudson, Xantrex......................................................................................... 21 

6.3 “Power Electronics for DER and Renewable Applications,” Jonathan 

Lynch, Northern Power Systems ....................................................................... 22 

6.4 “SMA America: Advanced Power Electronic Interfaces Workshop,” Kent 

Sheldon, SMA.................................................................................................... 23 

6.5 Session 4 Discussion.......................................................................................... 24 

ix 
7 Conclusions ...............................................................................................................................26

Appendix A: Agenda ..........................................................................................................................27

Appendix B. List of Attendees ..........................................................................................................29

Appendix C. Speaker Biographies....................................................................................................33

Appendix D. Workshop Presentations .............................................................................................36

Appendix E. Additional Resources.................................................................................................221

x 
1 Introduction 

The Advanced Power Electronics Interfaces for Distributed Energy Workshop, sponsored by 

the California Energy Commission Public Interest Energy Research (PIER) program and 

organized by the National Renewable Energy Laboratory (NREL), was held Aug. 24, 2006, 

in Sacramento, California. 

The purpose of the workshop was to create a forum for a diverse range of distributed 

energy resource (DER) industry stakeholders to learn about experiences and related 

technologies and explore the issues and options for DER power electronics. It focused on 

the development of advanced power electronic interfaces for distributed energy 

applications and included discussions of modular power electronics, component 

manufacturing, and power electronic applications. 

1.1 Workshop Sponsor 

The California Energy Commission, California's energy policy and planning agency, 

forecasts energy needs, keeps historical energy data, licenses thermal power plants, promotes 

energy efficiency, develops energy technologies and renewable energy, and plans for and 

responds to energy emergencies. In 1996, the Electric Utility Industry Restructuring Act of 

1996 expanded the commission’s responsibilities by establishing the PIER Program. The act 

required that at least $62.5 million be collected each year from investor-owned utility 

ratepayers to fund public interest energy research. 

The PIER Program partners with individuals, businesses, utilities, and public and private 

research institutions to conduct research on promising technologies, products, and services. It 

focuses on: 

• Buildings end-use energy efficiency 

• Energy innovations small grant program 

• Energy-related environmental research 

• Energy systems integration 

• Environmentally preferred advanced generation 

• Industrial/agricultural/water end-use energy efficiency 

• Renewable energy technologies. 

Power electronics fall within the purview of the PIER Energy Systems Integration group. 

This group takes a systems engineering approach to the electricity delivery system and 

focuses on transmission research, distribution research, and the integration of DER into the 

power system. A significant part of this group’s $42 million research portfolio is committed 

to demonstrating the benefits of DER integration for utilities, regulators, and ratepayers. 

Power electronics, a key technology in this area, can reduce the costs of interconnection and 

improve the integration of DER technologies. 

1 
Toward this end, PIER has partnered with the NREL to address power electronics issues. 

Called the Advanced Power Electronics Interface (APEI) Initiative, this six-year, $20-

million-plus effort is a coordinated plan to develop a modular architecture for standardized, 

highly integrated power electronics interconnection technologies that will come as close as 

possible to “plug-and-play” for DER platforms. 

The goal of the APEI Initiative is to develop power electronics technology that improves 

and accelerates the use of DER systems. The objective is to reduce costs for DER and 

interconnections by developing standardized, high-production-volume power 

electronic modules. 

NREL is the U.S. Department of Energy’s premier research facility for renewable energy and 

energy efficiency research. As part of its mission, NREL has established a Distributed 

Energy Systems Integration group to facilitate the interconnection of DER with the electric 

power system (EPS). The Distributed Energy Systems Integration group focuses on testing 

and certification, standards and codes, technology development, DER applications, and 

regulatory issues. 

1.2 Workshop Structure 

The workshop provided a status update on DER power electronics designs, manufacturing 

approaches, and issues. PIER will use the information gathered to determine issues its 

research could address and strategies for the APEI Initiative. The information will also be 

used to develop a future California Energy Commission PIER request for proposals for an 

advanced power electronic interface. 

The workshop was organized into four sessions: 

• Experience With Modular Power Electronics 

• Advanced Concepts and Components 

• Modular Power Electronics 

• Power Electronics for Distributed Energy Applications. 

Sections 3 through 6 provide summaries of the workshop presentations. The full 

presentations are included in Appendix D. As an additional resource, a presentation by Dr. 

Alfred Engler, Institut für Solare Energieversorgungstechnik, is included in Appendix E.

2 
2 Workshop Introduction 

Mark Rawson, program lead of the PIER Energy Systems Integration team, opened the 

workshop by welcoming participants and providing background information about the 

APEI Initiative. 

The PIER Energy Systems Integration team uses a systems engineering approach in its work 

to integrate energy efficiency, demand response, DER, renewable energy, and energy storage 

into the EPS. It focuses on science and technology advancements in sensors and monitoring, 

power electronics, communications and controls, intelligent automated systems, and realtime operations. 

Two of PIER’s seven strategic objectives are addressed by the advancement of power 

electronics: 

• Enable optimal integration of renewables, distributed generation, demand response, 

and storage to the power system. 

• Improve cost and functionality of components to integrate demand response, 

distributed generation, and electricity storage into the system. 

The APEI Initiative, under the direction of PIER Energy Systems Integration and NREL, will 

facilitate the advancement of the power electronics industry by enabling the production of 

more cost-effective products. 

2.1 “Power Electronics for Utility Applications at the Department of Energy,” 

Imre Gyuk, Department of Energy 

Power quality is critically important to today’s digital economy. In fact, common nominal 

power quality events cost the nation about $52 billion each year. To address power quality 

issues, the Energy Storage program within the Department of Energy’s Office of Electricity 

Delivery and Energy Reliability has researched a number of advancements in energy storage 

technologies and power electronics, including a large-scale uninterrupted power system 

(UPS) that could be factory-integrated, tested, and used in plug-and-play installations. 

Based on CBEMA curves (which were developed by the Computer and Business Equipment 

Manufacturers Association to simplify the modeling of system response and evaluate all 

factors in voltage deviations from the norm) from the Electric Power Research Institute, 

researchers determined that a system that could provide power for 15–30 seconds would 

cover 95% of all outages. A mobile, 2-MW, 15-second battery system was designed to meet 

these requirements. This system won an R&D 100 award and is now used throughout the 

country. A later generation, which provides 10 MW for 30 seconds, is now in service in a 

microchip plant in Arizona. Another, which uses a sodium sulfur battery rather than a lead 

acid array, provides peak shaving at a substation. 

Other areas of research have included optically isolated inverters; advanced heat exchangers; 

low-cost, modular, highly-reliable inverters; emitter turnoff switches; and transmission 

stabilization devices. 

3 
The emitter turn-off (ETO) switch, developed by Virginia Tech and North Carolina State, 

was conceived from the need for a faster, more powerful, and cheaper switch. The resulting 

product is 15–20 times faster than a gate turnoff thyristor and has three times the power of 

the more-expensive insulated gate bipolar transistor. This technology also was awarded an 

R&D 100. 

The transformerless STATCOM with energy storage was created through a collaboration of 

organizations with the goal of providing four quarter control with both real and reactive 

power. Although two-thirds of an example trailer-mounted installation employed 

supercapacitors, one-third made use of the ETO. 

Finally, a more recent project has addressed the power quality issues associated with a 48-

MW Bonneville Power Administration wind farm. Customer complaints and variable voltage 

led the administration to seek solutions. A trailer-mounted ETO STATCOM couple with grid 

power was one suggestion. The group is currently pursuing this option. 

Projects such as these are showing the potential of power electronics. In fact, a recent 

meeting that brought together representatives of the national laboratories, renewable and 

electricity research groups, and the Office of Science determined that power electronics and 

energy storage should be priority areas for investment. 

Future research plans include work with advanced materials, ETO deployment, thermal 

management systems, novel materials, silicon carbide switches, high-temperature materials, 

ionic fluids for electrolytes, advanced wideband gap system deployment, nano-structured 

materials, and diamond switches. 

2.2 “Power Electronics Research Assessment,” Forrest Small, Navigant 

In 2004, Navigant Consulting Inc. worked with PIER’s Energy Systems Integration team on 

research assessment and planning for power electronics. The goal was to identify research 

activities the commission could support to increase the penetration of DER in California. 

To do so, Navigant first surveyed stakeholders to identify their key business needs. It found 

that the expense of power electronics—as much as 40% of DER system cost—has inhibited 

the use of DER. It also found that the current performance of power electronics was lacking 

and hindering long-term commercial application. 

Navigant then analyzed the technology challenges related to these needs. It found: 

• A lack of standardization and inter- and intra-operability of power electronic systems, 

components, and the grid 

• A need for power electronic devices that are modular and scalable 

• A need for improvements in power electronic system packages. 

4 
Navigant next identified 10 potential research initiatives to address the technology 

challenges. It ranked the initiatives based on their relative impact to DER systems, their 

relevance to the public interest, and the existing gap between current and necessary research. 

Based on the rankings, it identified three key initiatives: 

• Standardize the interface between power electronics systems and the grid. 

• Standardize and improve the interoperability of power electronics components and 

systems. 

• Improve the scalability/modularity of power electronic systems and components. 

Navigant believes these initiatives offer the greatest potential to affect future development 

and recommended that the PIER team pursue them with a systems approach. These findings 

were the basis for the California Energy Commission to proceed with the APEI Initiative. 

2.3 Workshop Introduction Discussion 

• Who manufactures the ETOs in Dr. Gyuk’s projects?

The ETO is not being commercially manufactured. At this time, it is made only at the 

university. However, there is some interest, and manufacturers are being pursued. 

• It was mentioned that power electronics correspond to up to 40% of the cost of DER 

systems. Does that include motors and generators as part of power electronics? 

Navigant performed a round buildup of the cost of a representative DER system to 

determine what percentage of the cost would belong to power electronics 

components. Forrest Small, of Navigant, believes this counted only inverter and 

control systems. 

5 
3 Session 1: Experience With Modular Power Electronics 

3.1 “Power Electronic Building Blocks: Office of Naval Research Experience 

and Observations,” Terry Ericsen, Office of Naval Research 

In 1994, the Office of Naval Research (ONR) instituted the Power Electronics Building 

Blocks (PEBB) program, an effort to develop a universal power processor capable of 

changing any electrical power input into any voltage, current, and frequency output. The goal 

was to create a product that would enable high-volume production of small power electronics 

to reduce their cost and development time. The resulting PEBB is envisioned to be softwarereconfigurable, multi-purpose, “smart,” and universal (i.e., it replaces specialized devices 

such as power conditioners, inverters, and circuit breakers). However, numerous advances 

are still necessary. 

The ONR has identified several challenges to its overall ship design process. These include 

rule-based design, standard parts, increasing complexity, specifications and documents, and 

small sample statistics. 

However, there are other, more general, challenges as well. One example is the role of 

simulation. Today, as in the past, simulations are developed as an analysis tool. They are 

based on models of a real product to study variations in design. However, simulations can 

play a synthesis role in the process. In the future, simulations should be based on 

specifications and performed in the early stages of design to determine the final real product. 

Another example is the effect of the design cycle—or the lack of one. Because power 

electronics do not function in a vacuum, they should be developed in an iterative design cycle 

in which requirements influence products and vice versa. It was noted that the use of general 

models in the design process is more productive than the use of specific ones because they 

help developers avoid overly constrained problems. 

Then there is complexity. Complexity is a result of emergence. That is, complex systems 

display a behavior that cannot be predicted based on the behaviors of their individual parts. 

Complexity is not a product of the number of parts. Complex systems can be simplified 

through physics-based partitioning, the addition of intelligent active devices, and the creation 

of controlled and predictable system states at physics-based partitions. However, reducing 

complexity increases the detail, size, weight, and cost of the power electronics. Therefore, 

these traits must be reduced to enable practical application and overall simplification of 

complex systems. 

Three recent innovations will influence the future development of power electronics: (1) 

increased computing power; (2) the development of high-speed, low-cost controllers; and (3) 

system-simplifying concepts. These are important innovations that will touch on multiple 

aspects of development and enable new advances. 

6 
An additional problem relates to investor influence. Up to a point, if money is invested into a 

development process, the final cost of the product will decrease and performance will 

improve. Obviously, at some point, more money must be invested to extract diminishing 

performance returns. Between these is an optimal point, at which the balance between 

investment and performance is ideal. For investors, their influence is very high early in the 

development process, when their investments garner big returns on performance. But as 

progress is made, changes become more difficult, and investor influence weakens. Therefore, 

for effective development and maximum influence, investors must become involved early in 

the process, and developers must employ modeling and simulation to guide the process. 

All of these issues have influenced the vision and development of PEBBs. Other important 

influences include the concepts of partitioning, concurrent engineering, early validation, and 

universal, or “plug and play” components. 

Today, a working group headed by Narain Hingorani is developing an IEEE standard using 

the PEBB concept for electrical power systems. There are also some examples of PEBBs 

already in use. Three to five megawatts have been installed for a variety of applications. 

Finally, future needs also include modeling standards, benchmark models, a library of 

models, and a body of international volunteer experts for these efforts. 

3.2 “Integrated Power Electronics Building Block Modules, Converters, and 

Systems,” Fred Wang, Virginia Tech 

The Center for Power Electronics Systems (CPES), a National Science Foundation 

engineering research center, is focused on the development of integrated power electronics 

modules. Its vision is to follow the example of micro-electronics by achieving integrated 

functionality, a standardized interface, and a versatile product suitable for mass production. 

Power electronics interfaces are a key enabling technology for DER. They offer the potential 

of lower costs, higher reliability, and improved performance. To achieve this, other 

organizations are pursuing the conventional approach of improving the components, devices, 

and circuits of power electronics. CPES, however, has adopted an alternative approach of 

modularization, standardization, and integration to achieve economies of scale. It also 

emphasizes a system perspective in its work. 

CPES’ specific approaches include integrated load converters (including motor-converter 

integration and microprocessor-converter integration), power distribution converters, and 

integrated source converters. For each, CPES begins with basic research on the devices, 

materials, and technology and then moves to developing enabling technologies and, finally, 

engineered systems. Already, through research funded by ONR’s PEBB program and other 

sponsors, CPES has developed numerous integrated power electronics modules ranging from 

10 W to 10 MW. CPES researchers are now addressing the issues of a building block 

approach, architecture and partitioning, and interface characterization. 

CPES starts at the bottom with a topology and builds from that foundation up to application 

layer control in a hierarchical structure. This requires the correct control architecture and 

communication protocols. 

7 
Finally, CPES has realized additional benefits to integrated power converter functionality. 

These include power flow control; power management; power quality control; monitoring, 

diagnosis, and online mitigation; and protection. 

3.3 “Bricks and Buses,” Giri Venkataramanan, University of Wisconsin 

The largest markets for power electronics today are in relatively large-volume areas such as 

motor drives, power supplies, UPSs, and compact fluorescents. However, these are 

segmented markets, and it is unclear if DER can establish itself as a new market segment. 

To create a new market segment, DER power electronics must overcome challenges. For 

example, a typical inverter is a complicated piece of equipment. The power electronic, filter, 

transformer, and controller components form a jungle of wires and electronics. Because of 

this, power electronics applications are assembled by hand—even in mass production 

scenarios. This production process is expensive and inhibits cost reductions. If significant 

cost reductions are to be realized, automated assembly, fabrication, and compilation are 

necessary. Other constraints include low reliability, custom designs, and long design cycles. 

Therefore, the future of power electronics must include standardized input, output, and 

functionality; “compilable” cabinets; and fail-safe and plug-and-play capabilities as well as 

units compatible with multiple geometries. 

Modular systems are in production. Eaton has developed a molded case circuit breaker board 

into which input and output breakers, transient voltage surge suppressor modules, and card 

and voltage sensors can be plugged. Therefore, minimum assembly is involved. Rockwell 

has introduced a product line of several drives that are pre-engineered to work together. 

These incorporate control and communication cables interfaced through a bus and a line 

interface module that is pre-engineered for ease of integration. These are models for DER 

market development. 

8 
Several years ago, with support from the California Energy Commission and other sources, 

the University of Wisconsin – Madison began to develop a “bricks and buses” converter. 

This work involved demonstrating a concept prototype with electrical performance 

comparable to that of classically designed products, increased power density, modular 

packaging, and improved manufacturability. 

One result of this work was a 3.2-kW, single-phase inverter. The inverter integrates the 

switch gear, rectifier module, capacitor, inductor, and output. On the bottom, mechanical, 

power, and control buses are positioned for “brick” interconnection. Each of its modules is 

independently thermally managed. However, other models are also possible. 

The “bricks and buses” example offers standard depth and height dimensions but 

varied widths. In addition, it has variable volume, proportional scaling of the 

surface area, a decoupled power bus and signal bus, and a contained interconnect 

electromagnetic interference. 

However, there are still challenges. The cost, size, and lack of modularity of the many 

components are major barriers. For example, the prices of copper and steel, which are used 

for the magnetic elements, have increased substantially over the past 5 years. Many of these 

components can be produced with less expensive materials and in more modular structures. 

Such advances could make possible alternatives. An example is a system that could include a 

switch, throw capacitance, pole magnetics, and thermal management. These cells can be 

combined to increase power rating and number of phases. Other advanced concepts include 

air- and liquid-cooled designs and bus-centered assemblies. 

3.4 Session 1 Discussion 

• The initial PEBB program focused on Navy ship power systems. For that program, 

how many eventual manufacturers are there? And are their products compatible with 

one another’s, or are they just compatible within each company? 

The Navy is not a mass buyer, and it does not buy these types of systems frequently. So 

it is not an industry. To create an industry and bring down costs for the Navy, utilities 

and others must be involved. ONR has employed a spin-on/spin-off strategy to spin off 

its investments to companies such as ABB and Rockwell. So far, several PEBBs—

including one aboard a GLIB, or Great Lakes Icebreaker—have been put into use 

through this arrangement. 

Manufacturers have an incentive to adopt the PEBB process because of economies of 

up to five- to ten-time reductions in engineering costs. ONR’s next development will be 

plug-and-play units. At that point, it is expected that costs will start to be driven from 

the customer side. The question remains of how to provide incentives for this step. 

9 
• How realistic is it that PEBBs can accommodate distributed generation and storage 

in increasingly large power classes? More specifically, is the PEBB approach one 

that focuses within classes, or can it be used to cross classes of power 

electronics packages? 

The idea is to do both. In fact, as the various markets and industries progress, they are 

becoming more similar. For example, they are losing fuses and breakers as solid state 

becomes more common. The ABB SCS 5000, a medium-voltage system for ship 

drives, is a 20-MW system with no fuses or breakers. 

However, this may be a challenge for utilities that want to visually check switch gear 

and relays. In the ship system, this is not an issue because there are no uncontrolled 

generation sources and so no reason to employ fuses and breakers to protect the 

system from such threats. 

• The business paradigm also must change, and it is. In the past, the manufacturers 

have associated themselves with a particular application segment (e.g., drives or 

wind generation). But with converter modules or PEBBs, they must associate with a 

line based on power level rather than application. 

Eventually, this will mean original equipment manufacturers will be able to offer 

application solutions within short time frames, much like the computer industry. This 

is a difficult move for industry, but it is beginning to happen.

• If there is a failure in a module, is there some type of diagnostic to identify which 

module needs attention? Can that module be replaced, or must the entire block 

be discarded? 

At this point, this is not possible. However, it is the intent for the future. Upon failure, 

the module would shut itself off and electrically isolate itself from the other units. The 

long-term goal is modules that are “hot swappable,” meaning that they can be replaced 

without shutting the system down. 

This type of functionality will require a definition of an architecture, and the 

IEEE working group is working on one now. Another idea for such functionality 

uses “agents” located inside each PEBB. When the system is activated, the agents 

would communicate with one another to determine the incorporated functions and 

operate appropriately. This could lead to the development of dynamically 

reconfigurable systems.

10 
• What are the biggest barriers to industry adoption of a bricks and buses approach?

In approximately 2003, Dr. Venkataramanan held a workshop of power electronics 

industry representatives in Madison, Wisconsin. The feedback he received revealed 

hesitations to dismantle practices and systems designed for established industries 

(e.g., power supplies or motor drives). 

However, there has been change since that time, and some of the new thinking is 

being incorporated into new designs. Further, this workshop is focused on power 

electronics for DER, which is a new industry. It will likely be easier to work with all 

the players early on, before they are entrenched in practices and systems. 

11 
4 Session 2: Advanced Concepts and Components 

4.1 “Advanced Topologies for Distributed Energy Interface,” Ned Mohan, 

University of Minnesota 

The University of Minnesota has performed power electronics research at the detailed level 

of topologies. This work has included an ultra-compact, high-efficiency, hybrid converter for 

photovoltaics (PV) and fuel cells and a multi-port DC-DC converter. The multi-port DC-DC 

converter is a compact unit that works as an interface between two or more energy sources 

and a load. It allows power flow from different energy sources to a load and bidirectional 

flow for all sources (e.g., for a battery). The converter is intended for use in hybrid vehicles 

and residential homes/buildings. 

More recently, the university has been working to simplify the control of matrix converters to 

control motors and generators. It has found that silicon carbide-based converters, which can 

operate at very high temperatures, are particularly promising. 

The voltage-link power electronic system is common, but there are problems with its storage 

capacitor—and particularly with weight, cost, and reliability. In addition, the capacitor has 

problems with in-rush current, and it is difficult to integrate with motors. 

Matrix converters, however, have no energy storage element. They operate AC-AC and offer 

bidirectional power flow. The university used ideal transformers to simplify how switching 

signals are generated and therefore simplify matrix converter control. 

The university’s study then pushed the technology by incorporating an AC machine to 

improve its performance. It found it could almost double it. By taking an AC machine’s 

Wye-connection and opening it up and feeding it from matrix converters from both sides, it 

found it could eliminate bearing currents, deal with isolated voltages, reduce slab insulation, 

control input power factor, and increase power capability. In addition, because the converters 

take advantage of the new silicon carbide materials, they have the potential for reduced costs 

because they do not require expensive copper and steel. And finally, functionally, they are 

PEBBs. They eliminate the need for bulky storage capacitors. 

Future research on matrix converters will analyze the efficiency of the system, explore how 

to make the current ripple smaller, and determine ways to operate at lower frequencies. 

4.2 “Integrated Modules Simplify Systems Design,” John Mookken, 

SEMIKRON Inc. 

Power modules have evolved significantly since their introduction in the 1960s. Each 

generation has introduced improved power densities and new components, and each 

generation has evolved to integrate more components into the modules. Today, power 

modules integrate diodes, switching devices, gate drives, current sensors, voltage sensors, 

and temperature sensors. 

12 
The trend toward integration has several drivers, including a shorter time to market, easier 

system design and assembly, improved economics, and a reduced number of components. In 

addition, integration offers benefits such as customized solutions for regular prices, standard 

interfaces, and standard platforms. 

At SEMIKRON, the latest design is the SKAI, which also includes the digital signal 

processor controller, a move toward intelligence in the module. (However, the module is 

not yet fully “intelligent” because the software is not included.) This programmable module 

was developed with U.S. Department of Energy funding over a 3-year period that began in 

1999. It is an advanced design that begins to blur the boundary between power modules 

and motor drives. 

The SKAI consists of a core platform (which consists of the semiconductors and capacitor) and 

customizable components (i.e., the insulated gate bipolar transistors, digital signal processor, 

controller, power supply, gate driver, protection, and heat sink). SEMIKRON designed the 

module to work with various applications but incorporated flexibility into the design based on 

its customer experience. It found that its customers liked the product, but, because of its 

general design, it was not optimized for their needs. The customizable components offer them 

the flexibility to build an optimized solution while taking advantage of the benefits of 

standardization. Today, only about 5% of SKAI sales are for unmodified units. 

The SKAI can be configured using 600 V or 1,200 V insulated gate bipolar transistors with 

continuous AC output currents of 400 A rms or 300 A rms, respectfully. The module 

includes either a liquid-cooled or air-cooled heat sink. It is about the size of shoebox and can 

be manufactured in large quantities. All customizations are additions to the manufactured 

unit, so they do not affect manufacturing costs. The SKAI can be used for a variety of 

applications, depending on the customer’s need and software. 

SEMIKRON has experienced varying reactions to the standardized platform. It has generally 

found that its customers like the standardization concept—for their own product ranges. But 

most do not want outside products to be able to plug into their architecture. However, this is 

the general growth pattern in the industry and is likely to be overcome. For example, earlier 

power module designs from one company were eventually adopted by others so they could 

serve the replacement market. Customers especially like this situation because it results in 

competition. However, it makes the product a commodity, and power module manufacturers 

have incentives to resist this situation. 

4.3 “Distributed Energy Advanced Power Electronic Interfaces,” Ben 

Kroposki, National Renewable Energy Laboratory 

Distributed energy applications include wind turbines, PV arrays, fuel cells, microturbines, 

and reciprocating engines. Although they are not new technologies, they are receiving 

increased attention today because of their ability to provide combined heat power, peak 

power and demand reduction, backup power, improved power quality, and ancillary services 

to the power grid. 

13 
One concern with distributed energy applications is their interconnection with the grid. 

Interconnection technologies have the potential to simplify this issue by performing the 

integration for all DC generation technologies as well as for generators. However, in addition 

to the basic integration, they can provide broader functions. Many small distributed energy 

systems already incorporate these functionalities in their inverter technology. Larger systems, 

however, generally incorporate these functions through separate pieces of equipment. 

Power electronics have the potential to improve the interconnection of distributed energy 

applications and the power grid. In one scenario, they are used as an interface between the 

DER unit and the grid. In another, they are used to facilitate the creation of “islands” or 

“microgrids” by replacing circuit breakers. 

Such applications can have many benefits. For example, the use of power electronics to 

interconnect DER can improve operating efficiencies, improve power quality, provide Var 

support and voltage regulation, reduce distributed energy fault currents, allow 

interoperability of multiple sources, and provide for standardization and modularity. 

Key to the interconnection of distributed energy applications are the ongoing efforts of the 

IEEE 1547 working groups. These groups are developing a series of standards to address the 

technical requirements interconnection. IEEE 1547 Standard for Interconnecting Distributed 

Resources With Electric Power Systems, the first of the series, was approved in 2003, and 

1547.1 Standard for Conformance Test Procedures for Equipment Interconnecting 

Distributed Resources With Electric Power Systems was approved in 2005. These standards 

provide a foundation for efforts to develop power electronics-based interconnection 

equipment. Five more standards in the series are under development and will provide more 

guidance. In the future, a possible standard may address power electronics interface 

specifications. NREL, through support from the Department of Energy Office of Energy 

Research, is leading these efforts. 

Further, the tests outlined in IEEE 1547.1 to ensure proper interconnection have been 

incorporated into Underwriters Laboratories (UL) 1741 Inverters, Converters, Controllers, and 

Interconnection System Equipment for Use With Distributed Energy Resources. This provides 

manufacturers of power electronics or other interconnection equipment with a consistent set of 

testing requirements for their products. UL 1741 was updated to include these requirements 

last November, and manufacturers have 18 months from that date to comply. 

NREL also performs testing and evaluation of DER systems and components at it Distributed 

Energy Resources Test Facility in Golden, Colo. This facility will be used for testing and 

evaluation of equipment developed as a result of the upcoming PIER Advanced Power 

Electronics Initiative solicitation. 

14 
4.4 Session 2 Discussion 

• Presentations in the first session focused on the different functional modules in the 

PEBB concept and their standardization, but John Mookken focused on standardizing 

only the power module. What cost savings can be realized from standardizing only 

that piece?

The standard power module includes the driver and controller, but both can be 

replaced, if the customer desires. The biggest cost contributors are the capacitor, the 

current sensor, and the silicon. 

• Five percent of SEMIKRON’s orders for the SKAI were for off-the-shelf units. What is 

the cost increase for changes to those units?

Because no manufacturing modifications are necessary to accommodate the changes, 

the cost on a per-unit basis is virtually insignificant. The only changes that 

significantly affect cost are adding more capacitance into the module or scaling up the 

power level. 

• Does the SKAI come with a warranty, and if so, do customizations affect the warranty?

SEMIKRON offers a 2-year warranty for the SKAI. Customized models are 

also covered. 

• First, manufacturers have until May 2007 to comply with the requirements of 1547.1 

and UL 1741, and UL is not yet prepared to certify to 1547. However, utilities are 

beginning to require 1547.1 certification. This is, in effect, locking the manufacturers 

out of some utility districts. Second, 1547.1 introduced new requirements that resulted 

in manufacturers having to redesign and recertify their equipment. This is a very 

expensive process. Will the other standards in the 1547 series have similar effects?

IEEE 1547 and IEEE 1547.1 are actual standards, but the rest of the series consists of 

guides and recommended practices. Therefore, few or no requirements should be 

developed as part of their introduction (with the possible exception P1547.6 and 

operation on distribution secondary networks). Unfortunately, for the 1547 and 

1547.1 requirements, meeting them is a cost of doing business in the DER market. 

UL1741 provides a way to certify products to those standards. 

• There has been a lot of discussion of standards. Are the future PEBB standards for 

consumers or application suppliers? 

The consumer likely has the most to gain from a standard. As mentioned earlier, this 

would eventually result in a commodity product and lower prices. This is why some 

manufacturers resist the concept of standards. 

15 
• There is resistance to standardization, but there are benefits also. The market 

increases with commoditization because of lower costs and standardization. 

However, it can also work the other way. Consumers want the lowest possible price. 

In some instances, they may want a custom solution (e.g., they do not need a standard 

part) to further lower costs. 

• Have the matrix converters discussed by Dr. Mohan been tested to confirm the 

doubling of power? 

Not yet. The idea is only in the conceptual and analytical stages at this point. 

• Is the NREL test facility able to implement and test microgrid configurations? 

The facility is flexible and includes a variety of distributed generation sources. It can 

be used for low-voltage configurations of less than 600 V. Additional equipment 

would be necessary for medium-voltage configurations. 

• Are their problems with the 60-Hz harmonics in the matrix converter because there 

aren’t any passives? 

No. Matrix converters can synthesize any frequency desired at the output. In the past, a 

drawback was that the output voltage was only 86% of the input voltage. The new 

configuration achieves 186%. It also allows control of the input power factor. However, 

this is all analytical at this time. It has only been simulated through software. 

• One problem with matrix converters is their lack of fault tolerance. How will this be 

addressed for interconnection applications? 

There must be protection against spikes, but matrix converters are in some ways more 

benign than others. 

• What is the IEEE standard for microgrids and intentional islanding? 

IEEE P1547.4 Guide for Design, Operation, and Integration of Distributed 

Resource Island Systems With EPS is currently under development. It is not a full 

standard but rather a guide of how to intentionally island parts of the power system 

correctly and safely.

16 
5 Session 3: Modular Power Electronics Distributed Energy 

Applications 

5.1 “Modular and Scalable Power Converters in the Uninterruptible Power 

Supply Industry,” Ian Wallace, Eaton 

Sensitive (e.g., data centers, servers, and clinical laboratory equipment) and critical (e.g., 

broadcast transmitters, industrial process, and government facilities) power applications 

require high quality. Even brief interruptions in power supply or quality can severely affect 

function and profits. 

The EPS typically provides 99.9%, or three “nines,” reliability to its users, which is 

equivalent to roughly 9 hours of outage per year. However, for mission-critical applications, 

this is often not sufficient. These applications require “high nines” reliability, or reliability on 

the order of 99.9999% or more. 

To achieve “high nine” reliability, most of these systems rely on two elements. The first is 

multi-source power, or the use of some combination of utility power, generators, batteries, 

flywheels, ultracapacitors, etc. The second is a UPS, located between the power sources and 

the load. In the event of a power quality or availability problem, the UPS switches the load’s 

source to avoid a power outage or equipment damage. 

To be effective, UPSs must employ parallel redundancy to ensure availability and avoid 

single-point failures. They must be easily expanded to accommodate increased capacity and 

growth, and they must have a low mean time for repairs. 

Today, the UPS market is growing. It is projected the industry will achieve 10% growth in 

revenue per year and a 4% reduction in UPS price. In the market, the drivers for UPS 

technology and market growth include: 

• Low installation cost 

• Low operating cost 

• High power quality utility interface 

• High power density 

• Serviceability 

• Multi-source compatibility 

• Monitoring, diagnostics, and prognostics 

• Maintenance services. 

Past UPSs were positioned to meet these needs, but they faced two technical hurdles: the 

control of two or more paralleled AC power sources and the elimination of all systems-level 

single points of failure. These systems were limited to six “nines” or less. 

17 
Today, Eaton uses Hot Sync technology, a communicationless parallel system, to achieve 

seven “nines.” The elimination of communications enables the use of multiple units 

connected together and eliminates single points of failure. The identical modules operate 

together as peers to share and balance the power. This modular system provides flexibility 

and scalability to Eaton’s UPS systems. 

Based on this technology, Eaton has developed product lines that can be expanded 

incrementally for capacity, redundancy, and volume. In one approach, the control contains 

overhead to accommodate the incorporation of future modules, and the modules are 

standardized “bricks.” In another, full modular products are hot-swapped on a standard rack. 

5.2 “Distributed Energy Applications Leverage High-Volume, Modular Power 

Converters,” Perry Schugart, American Semiconductor 

Regardless of the size of the system, power electronics are often the last component to be 

designed. Frequently, the power electronics designers are forced to accommodate the rest of 

the system by squeezing their product into whatever space is left. Often, however, there are 

significant benefits to planning for the power electronics early in the design process. 

American Superconductor has developed a PEBB with support from the ONR. The PM1000 

is a programmable building block power converter designed for high-volume production and 

rapid development. Each module is fully contained with controls and power supplies. The 

PM1000 uses a power pole architecture and can be air- or liquid-cooled. It is designed to 

accommodate customer special needs without converter board modifications. The PM1000 

offers two digital signal processors and four operating programs as well as a configurable 

graphical user interface. 

The modularity of the PM1000 allows rapid development of power converters and power 

conversion systems. In addition, its standard power pole enables high-volume production, 

low cost, and increased reliability. The use of the PM1000 allows developers to avoid the 

time and cost of design, development, iteration, integration, and production. American 

Superconductor estimates this saves developers 1 year of development time and 

approximately $2 million. 

Another product offered by American Superconductor is a developer kit, which includes a 

PM1000, a converter interface, a graphical user interface, a software package, and fiber optic 

cable with a connector. The software can be changed out to change functionality. For 

example, a unit may first be used as an active rectifier but later switched to a DC-DC 

converter. No hardware changes are required. 

These developer kits cut time to operation even more. For example, a fuel cell manufacturer 

bought two of these kits to demonstrate a new concept for providing power to the grid. The 

demonstration was operational in less than a week. 

18 
A related development kit is designed for multiple-converter systems and can use any 

converter type (e.g., three-pole or six-pole). This system also allows the use of proprietary 

control algorithms. This kit is particularly applicable to DER applications. American 

Superconductor also offers the PM2000, a higher-power version of the PM1000. 

5.3 “Modular Inverters for Distributed Generation,” Matt Zolot, UQM 

UQM’s focus is on high-performance, power-dense, energy-efficient motors and power 

electronics for vehicle electrification. Over the past few years, interest has increased in the 

potential to connect hybrid vehicles to the power grid. These vehicles could conceivably 

provide peak-shaving power or other grid support and charge themselves from grid power to 

achieve true electric hybrid status. 

However, the automotive industry has different requirements for DG converters if they are to 

be packaged within vehicles. To be successful, the converters would need to be high-voltage, 

high-density, lightweight, rugged, and low-cost. 

UQM’s general specifications for a grid-connect inverter include an input voltage of 150–

360 V, a power output of up to 5 kW, 90% or more efficiency, galvanic isolation, and a 

grid and standalone operation of 50/60 Hz. In addition, the unit must meet appropriate UL 

and IEEE standards. 

UQM uses a Mathworks autocoding setup that takes advantage of existing in-house 

capabilities to simplify the control design process. This approach also allows researchers to 

perform simulations to test the code before it is downloaded to hardware. This setup will be 

used for the DER work to allow for advanced signal processing, true sine wave generation, 

and various phase operations. 

After analyzing the trade-offs between the performance, cost, and packaging of higherintegration modules and discrete component and the benefits of component-, board-, and 

package-level modularity, UQM chose to pursue smaller modular products. 

The UQM modular inverter allows incremental additions of 1.7 kW to a 1.7-kW base, up to 5 

kW. There is also a package design in which the modularity comes from components added 

to a board. A DC front end provides 5 kW and interfaces with the inverters. The whole 

system can then be duplicated and multiple systems coupled together. The output voltage can 

be configured in various ways. 

The goal of a modular system is to prevent redesign to enable high-volume production and 

reduce costs. However, to reach this goal, some challenges must be overcome. One challenge 

is the actual interconnection. To be truly useful, it must be simple enough for non-specialists 

to accomplish. Another involves communication between modules and packages. IEEE 

standards do not currently address this, so there is no standard for communication between 

different products. Another challenge is anti-islanding. Although it is not a challenge for the 

DER industry, it is a new concept for the automotive industry and must be considered. 

Finally, there must be a market. At this point, it is unclear if or how the market for such 

applications may develop. 

19 
5.4 Session 3 Discussion 

• Why are the automotive units only 5 kW? 

For light-duty vehicles, this is about right. Traction and heavier-duty uses would 

require more. 

• Approximately what volumes of the PM1000 are being produced?

American Superconductor is producing hundreds of the converter per year. 

• What sort of list price, in dollars per watt, does the PM1000 have? And what is 

smallest power increment?

Currently, there is essentially one power size. The three-phase unit is 175 kilowatts. 

The six-pole is about twice that. 

The developer kit, which is for three-pole configuration, is just less than $20,000. 

However, a volume purchase of the three-pole converter would garner a lower price 

per unit. The developer kit is intended for small volumes. Overall, however, the 

biggest cost savings come from the avoidance of development costs. 

• Do these products have warranties, and if so, what is the length?

The Eaton UPS products carry warranties of 1–2 years. The American 

Superconductor products come with base warranties of 1 year and offer the option of 

an extended warranty. The UQM product is still under development. 

• It seems 1–5 years seem to be the lifespan of warranties. What components are 

failing?

Electrolytic capacitors and fans often have the shortest lifetimes, but warranties are 

not necessarily indicative of lifespan. In addition, service contracts are an important 

offering to extend performance. 

Another consideration is the trade-off between lifespan and cost. Longer life spans 

will require increased costs. There is a balance that must be determined. 

20 
6 Session 4: Power Electronics for Distributed Energy 

Applications 

6.1 “Power Electronics Conversion for Distributed Energy Applications,” 

Alex Levran, Magnetek Inc. 

Magnetek is a power electronics company that develops products for various applications, 

including DER. Its DER products serve wind turbines, PV arrays, energy storage, fuel cells, 

variable speed generation, and microturbines. Magnetek serves both residential and 

commercial markets. 

DER applications have specific requirements that must be considered in the design of power 

electronics. For example, they must meet grid connection and anti-islanding standards and 

technical requirements. They must achieve high efficiencies in both power conversion and 

energy harvesting, and they must have compact designs. In addition, power electronics for 

DER must be reliable and cost-competitive, and they must be capable of communications and 

remote monitoring. 

Magnetek’s strategy is to lead the power electronic interface market for alternative 

energy systems. Its approach employs a common platform and building blocks into a 

scalable, modular, compact design that can be used for multiple DER sources. It uses 

high-efficiency, reliable converters; primary energy source control; high power densities; 

and system-level control. 

Magnetek anticipates several trends in the future of DER technologies. For inverters, new 

topologies and improved control algorithms will improve performance. Improvements will 

also be realized in thermal management devices, driver and sensing circuits, and capacitors 

and magnetic devices. In addition, silicon will be used for more components, and medium 

voltage will become more common. Magnetek also predicts the expansion of modular 

designs and more flexibility, scalability, and cross-technology platforms. 

6.2 “Xantrex Power Electronics for Renewable Energy System Applications,” 

Ray Hudson, Xantrex 

Xantrex is a power electronics company that is focused on the renewable power, portable and 

mobile power, and programmable power markets. It offers products for the solar, wind, and 

backup power areas of DER. 

For solar, the function of the power electronics is to convert the DC source power to AC 

power for use by loads or the electricity grid. The solar grid-tied inverters do not include 

backup power capability; they only allow the provision of PV power to the electricity grid. 

Off-grid inverters, in contrast, can provide backup power or primary power in locations 

without access to the grid. Xantrex offers battery-based, single-phase grid-tied, and threephase grid tied inverter lines. It also offers a charge controller product. 

21 
These inverters are crucial elements of solar array systems. They provide the user interface 

and key safety features. However, they are also very complicated and are often perceived as a 

weak link in the overall system because of past reliability issues. For example, solar array 

panels come with 20–30 year warranties; inverters come with 5–10 years. 

Xantrex’s key requirements for solar application inverters include high efficiency, 

advanced communication capabilities, low weight and part count, a sealed design, and 

standards compliancy. 

For wind applications, the role of power electronics is to convert the variable frequency and 

voltage AC power from the turbine(s) into grid-compatible AC power. Unlike PV systems, 

wind-based generation must meet Federal Energy Regulatory Commission ride-through 

requirements. Xantrex offers products for both the commercial and residential scales. 

In addition, Xantrex has developed power electronics for other DER technologies, including 

fuel cells, microturbines, advanced energy storage systems, and hybrid systems. However, 

this work has been relatively small-volume. 

In the future, Xantrex forecasts that power electronics manufacturers will move toward 

optimal system design that includes the balance-of-system components. The market will also 

see improved performance, with higher reliability, higher efficiency, longer life spans, lower 

costs, and simplified installation. For DER, Xantrex anticipates higher penetration levels on 

the EPS and a merger between the conflicting requirements for grid-tied wind turbine and PV 

applications. It also projects a “feed in” tariff incentive to reward the delivery of electricity 

and encourage the optimization of all DER system components. 

6.3 “Power Electronics for DER and Renewable Applications,” Jonathan 

Lynch, Northern Power Systems 

Northern Power Systems works on systems integration and engineering procurement, but it is 

steadily expanding its products and services, including those for renewable DER applications. 

Through market observation and experience gained from its own installations, Northern 

recognized a need for power electronics. It also recognized that power electronics were often 

the last part of the system to be considered and that this hindered performance. It saw 

opportunities for advanced power electronics to enable simpler interconnections, advanced 

power system architectures, utility distribution system support, increased DER ancillary 

support, and increased DER penetration. 

Based on these observations, Northern determined its power electronics focus. The company 

works primarily on applications of 500 kW or more and uses its PowerRouter control system 

to enable advanced power system architectures. It is also developing a line of products to 

support these systems. 

22 
Northern’s FlexPhase power converter platform is a modular converter system that 

accommodates applications from 500 kW to multiple megawatts. It is available in 480 V and 

690 V and contains configurable, rack-in power modules. The modules can be quickly 

replaced, and they contain intelligence. A system controller provides overall coordination. 

The benefits of the FlexPhase platform include its modularity, performance, size, and cost. 

The modular design of the system enables a low mean time to repair, which is particularly 

important in remote applications. It also allows serial production, which decreases 

manufacturing costs, and standard sizing. 

Northern is now using power electronics with conventional DER to standardize the grid 

interface, eliminate fault current contributions, add variable speed capability, and enable 

advanced architectures. Other recent efforts include the Power Distributor, which uses a 

power converter to provide distributed generation to multiple services; a DER utility 

interface switch, and the SmartView DER management system. 

6.4 “SMA America: Advanced Power Electronic Interfaces Workshop,” Kent 

Sheldon, SMA 

SMA America focuses on solar technology but also has product areas in communications 

and control, railway technology, and advanced energy systems. Within the solar division, 

about 80%–85% percent of SMA’s business is for grid-tied units. SMA’s product line 

includes residential PV, small wind, and hydro; commercial PV; and backup power and 

off-grid inverters. 

SMA believes that inverters are becoming a commodity, much like solar panels have. 

Maximum achievable efficiencies of 97%–98% are being reached, so cost is the only area for 

development and improvement. However, products can be differentiated based on strengths. 

At SMA, the strength is communications and control. 

SMA offers a Web box communication hub and system logger. This product logs every 

inverter on a system and stores the information in data files for customer use. This 

technology will be especially useful as renewable energy credit trading becomes more 

common, and it enables services such as performance analysis and system alarms. 

Another SMA differentiation is its use of AC coupling. In the United States, most off-grid 

and backup power systems are connected through battery storage. In AC coupling, SMA 

connects the system through an inverter that controls power quality to the load. This design 

provides an adaptable system and achieves 96% efficiency to loads. 

Recent innovations in SMA power electronics include optic-cooled forced air cooling, an 

integrated aluminum enclosure and heat sink, Ethernet communication, and a load-break 

rated DC fused disconnect. SMA has also introduced a transformerless, 8-kW grid-tied PV 

inverter in Europe that has achieved 98% peak efficiency. Future products include a power 

balancer to correct imbalance of multiple inverters on three-phase systems. 

23 
SMA identified several challenges in today’s power electronics market. These include 

pressure to further reduce prices, high competition, high certification costs, and increasing 

material costs. However, it also sees promising developments for the future. For future 

success, SMA believes there must be a shift to performance-based incentives, an 

acceptance of transformerless inverter technologies, and easing of regulatory and 

certification requirements. 

6.5 Session 4 Discussion 

• Are the megawatt-scale inverters for the large wind projects UL-listed? Do they 

conform to UL 1741, or are there other requirements that they must meet?

They do not go through UL, and there is not a specific standard for them other than 

safety requirements. Generally, at these sizes, the turbines are “behind the fence” of 

the utility and are not subject to UL authority. 

• What is the longest warranty offered on the DER-type inverters?

The standard warranty is 5 years, although some companies also offer extended 

warranties for a fee. The 5-year standard was influenced by California Energy 

Commission requirements. 

• There was a reference to ride-through in wind installations versus anti-islanding in 

PV installations. Is the PV is on the distribution system and the wind on the 

transmission system?

Yes, that is a difference. Because these systems interconnect at different levels of the 

EPS, they may have different interconnection rules. 

• Is there any standard to qualify digital signal processor software?

Yes, UL 1998. 

For a utility application, is there any standard requirement for validation of 

the code?

No attendees were aware of any such requirements. 

Are there standards for electromagnetic compatibility of internal components of 

digital signal processor chips or power electronics?

There are no standards, but there are techniques that can be used to check for this. 

24 
• Where do you think price points can be on megawatts-size power electronics if you 

produce 100 MW per year? 

Price points are variable and depend on the product and its specifications. 

• Have the inverter companies considered their future business plans? Perhaps the 

commoditization of inverters will not be a bad thing if it is approached correctly.

Not everyone agrees that inverters will become a commodity. However, much of the 

future will depend on the degree that the industry moves to vertical integration, the 

level of competition and the number of competitors, and the variations allowed in the 

products while meeting standards requirements. 

It is difficult for companies in this industry to create long-range plans because the 

market environment is very fluid. The regulatory climate and incentives change 

frequently, and so do material prices. One option to avoid all of these challenges may 

be pre-competitive cooperation, but this is not the way the industry is currently headed. 

• What could increase the reliability of your product lines?

Several things could and do help, including improvements in installation and installer 

knowledge, inverter technology maturation, the use of proven reliability techniques, 

improved simulation, and service contracts. 

• Other than cost, is there anything about the semiconductors that limit inverter 

performance?

Yes, the actual losses in the power electronics. They can be about 3%–4%. 

• Can inverters be designed in such a way that testing costs can be reduced?

The UL requirements are not yet known, and how the tests will be performed is not 

know. Easier test points can be added, but the standards must be known first. 

In addition, IEEE 1547.1 addresses testing of the black box, the whole package. Even 

if individual components of the unit have passed testing individually, it requires that 

they be tested again as part of the full system. 

25 
7 Conclusions 

The Advanced Power Electronics Interfaces for Distributed Energy Workshop was organized 

to gather information about the status of power electronics technologies. Through workshop 

presentations and discussion, several important themes emerged. These included: 

• The need for a standardized interface for power electronics 

• The importance of scalability in power electronics 

• The importance of modularity in power electronics 

• The need for power electronics to perform with high reliability and mean time 

between failure 

• The need to reduce the cost of power electronics components and address the 

increasing cost of current materials 

• The reluctance of industry to forfeit proprietary designs for a standardized interface 

and the threat/opportunity of commoditization 

• The need for longer warranties for power electronics products 

• The need for improved certification scenarios and lower-cost certification methods 

• The need to plan for power electronics early in the system design processes to reduce 

cost and increase effectiveness 

• The recognition that power electronics interface manufacturing will compete in a 

global market. 

PIER will use the information gathered to determine issues its research could address and 

strategies for the APEI Initiative. The information will also be used to develop a future 

California Energy Commission PIER request for proposals for an advanced power 

electronic interface. 

26 
Appendix A: Agenda 

27 
Agenda

Advanced Power Electronics Interfaces for DE Workshop 

Thursday, August 24, 2006 

Sponsor: California Energy Commission 

Location: 1516 9th Street Sacramento, CA

A WORKSHOP TO FOCUS ON THE STATUS OF DEVELOPMENT OF ADVANCED POWER ELECTRONIC INTERFACES FOR 

DISTRIBUTED ENERGY APPLICATIONS AND A DISCUSSION OF MODULAR POWER ELECTRONICS, COMPONENT 

MANUFACTURING, AND POWER ELECTRONIC APPLICATIONS

8:00 - 8:10 Welcome and Introductory Remarks, Mark Rawson, California Energy Commission

8:10 - 8:25 Power Electronics for Utility Applications at the Department of Energy, Imre Gyuk, DOE

8:25 - 8:40 Power Electronics Research Assessment, Forrest Small, Navigant

Session 1: Experience with Modular Power Electronics - Chair: Bernard Trenton, CEC 

EXPERIENCE WITH MODULAR POWER ELECTRONICS FROM THE POWER ELECTRONICS BUILDING BLOCK 

PROGRAM, INTEGRATED POWER ELECTRONICS MODULES AND BRICKS AND BUSES APPROACH

8:40 - 9:00 PEBB Program Experience, Terry Ericsen, Office of Naval Research

9:00 - 9:20 Integrated PEBB Modules, Converters, and Systems, Fred Wang, Virginia Tech

9:20 - 9:40 Bricks and Buses, Giri Venkataramanan, University of Wisconsin

9:40 - 10:00 General Discussion 

10:00 - 10:30 BREAK 

Session 2: Advanced Concepts and Components - Chair: Dick DeBlasio, NREL 

ADVANCED CONCEPTS FOR POWER ELECTRONICS CONVERTER DESIGNS INCLUDING MATRIX AND MULTI-PORT 

CONVERTER, MANUFACTURING POWER ELECTRONIC COMPONENTS AND ADVANCED FUNCTIONALITY FOR 

DISTRIBUTED ENERGY APPLICATIONS. 

10:30 - 10:50 Advanced Topologies, Ned Mohan, University of Minnesota

10:50 - 11:10 Integrated Modules Simplify Systems Design, John Mookken, SEMIKRON Inc. 

11:10 - 11:30 Power Electronic Interfaces, Ben Kroposki, NREL

11:30 - 12:00 General Discussion 

12:00 – 1:00 Lunch (on your own) 

Session 3: Modular Power Electronics Distributed Energy Applications - Chair: Jose Palomo, CEC

HIGH VOLUME POWER ELECTRONICS DESIGN AND MANUFACTURING CHALLENGES AS WELL AS CURRENT 

DISTRIBUTED ENERGY APPLICATIONS THAT USE THE MODULAR APPROACH

1:00 – 1:20 Modular and Scalable Power Converters in the UPS Industry, Ian Wallace, Eaton

1:20 – 1:40 Distributed Energy Applications Leverage High Volume, Modular Power Converters- Perry Schugart -

American Superconductor

1:40 – 2:00 Modular Inverters for Distributed Generation, Matt Zolot, UQM

2:00 – 2:30 General Discussion 

2:30 – 3:00 BREAK 

Session 4: Chair: Power Electronics for Distributed Energy Applications - Chair: Holly Thomas, NREL

CURRENT POWER ELECTRONICS IN THE RENEWABLE AND DISTRIBUTED ENERGY MARKETS

3:00 – 3:20 Magnetek Power Electronics - Alex Levran, Magnetek, Inc.

3:20 – 3:40 Xantrex Power Electronics for Renewable Energy System Applications – Ray Hudson, Xantrex 

3:40 – 4:00 Power Electronics for DER & Renewable Applications, Jonathan Lynch, Northern Power Systems

4:00 – 4:20 SMA Power Electronics – Kent Sheldon, SMA

4:20 – 5:00 Wrap-up for the day and general discussion 

28
Appendix B. List of Attendees 

Allen, Jennifer 

California Energy Commission 

1516 9th St., MS 43 

Sacramento, CA 95814-5512 

(916) 653-0291 

jallen@energy.state.ca.us 

Alvarez, Manuel 

Southern California Edison 

(916) 441-2369 

alvarem@sce.com 

Balog, Robert 

Smart Spark Energy Systems 

60 Hazelwood Drive 

Champaign, IL 61820 

(217) 344-6044 

R.Balog@SmartSparkEnergy.com 

Basso, Thomas 

NREL 

1617 Cole Blvd. 

Golden, CO 80401-3393 

(303) 275-3753 

thomas_basso@nrel.gov 

Briere, Michael 

International Rectifier 

1521 E. Grand Ave. 

El Segundo, CA 90245 

(310) 252-7124 

mbrierel@irf.com 

DeBlasio, Richard 

NREL 

1617 Cole Blvd. 

Golden, CO 80401-3393 

(303) 275-4333 

dick_deblasio@nrel.gov 

Erickson, Robert 

University of Colorado – Boulder 

Engineering Center, OT 356 425 UCB 

Boulder, CO 80309-0425 

(303) 492-7003 

rwe@colorado.edu 

Ericson, Terry 

ONR 

875 North Randolph St., Suite 1425 

Arlington, VA 22203-1995 

Gyuk, Imre 

Department of Energy – Office of 

Electricity Delivery & Energy Reliability 

1000 Independence, OE-10 

Washington, DC 20586 

(202) 586-1492 

Imre.Gyuk@hq.doe.gov 

Hingorani, Narain 

26480 Weston Drive 

Los Altos Hills, CA 94022, 

(650) 941-5240 

nhingorani@aol.com 

Hudson, Raymond 

Xantrex Technology Inc. 

161-G South Vasco Road 

Livermore, CA 94551 

(925) 245-5421 

ray.hudson@xantrex.com 

Johnson, Robert 

Cal Poly, San Luis Obispo 

1228 Bordeaux St. 

Livermore, CA 94550 

(805) 550-7535 

rhoberto@gmail.com 

29 
Kramer, Bill 

NREL 

1617 Cole Blvd. 

Golden, CO 80401 

(303) 275-3844 

bill_kramer@nrel.gov 

Kroposki, Benjamin 

NREL 

1617 Cole Blvd. 

Golden, CO 80401-3393 

(303) 275-2979 

benjamin_kroposki@nrel.gov 

Kulkarni, Pramod 

California Energy Commission 

1516 9th St., MS 43 

Sacramento, CA 95814-5512 

(916) 654-4637 

pkulkarn@energy.stare.ca.us 

Levran, Alexander 

Magnetek 

8966 Mason Ave. 

Chatsworth, CA 91311 

(818) 727-2216 

alevran@magnetek.com 

Lutz, Jon 

UQM Technologies Inc. 

7501 Miller Drive, P.O. Box 439 

Frederick, CO 80530 

(303) 278-2002 

jlutz@uqm.com 

Lynch, Jonathan 

Northern Power 

182 Mad River Park 

Waitsfield, VT 05673 

(802) 583-7224 

jlynch@northernpower.com 

 

Mohan, Ned 

University of Minnesota Twin Cities 

Campus - Department of Electrical and 

Computer Engineering 

200 Union St. S.E. 

Minneapolis, MN 55455 

(612) 625-3362 

mohan@ece.umn.edu 

Mookken, John 

SEMIKRON Inc. 

11 Executive Drive 

Hudson, NH 03051 

(603) 883-8102 Ext. 145 

john.mookken@semikron.com 

Nichols, David 

Rolls-Royce Fuel Cell Systems 

13030 Heatherstone Circle 

Pickerington, OH 43147 

(614) 755-2768 

david.nichols@rolls-royce.com 

Palomo, Jose 

California Energy Commission 

1516 9th St., MS 43 

Sacramento, CA 95814-5504 

(916) 654-4388 

jpalomo@energy.state.ca.us 

Pink, Christopher 

NREL 

1617 Cole Blvd. 

Golden, CO 80401-3393 

(303) 275-3758 

chris_pink@nrel.gov 

Rawson, Mark 

California Energy Commission 

1516 9th St., MS 43 

Sacramento, CA 95814-5504 

(916) 654-4671 

mrawson@energy.state.ca.us 

 

30 
Schugart, Perry 

American Superconductor 

15775 W. Schaefer Court 

New Berlin, WI 53151 

(262) 901-6036 

psehugart@amsuper.com 

Sheldon, Kent 

SMA America 

P.O. Box 5049 

Livermore CA 94551-5049 

(530) 273-4895 

ksheldon@sma-america.com 

Small, Forrest 

Navigant Consulting 

77 South Bedford St., Suite 400 

I Burlington, MA 01803 

(781) 270-8455 

fsmall@navigantconsulting.com 

Smedley, Gregory 

One-Cycle Control Inc. 

13844 Alton Parkway, Suite 137 

Irvine, CA 92618 

(949) 275-0581 

gsmedley@onecyclecontrol.com 

Soinski, Art 

California Energy Commission 

1516 9th St., MS 43 

Sacramento, CA 95814-5504 

(916) 654-4674 

asoinski@energy.state.ca.us 

Steeley, William 

EPRI Research Institute 

3420 Hillview Ave. 

Palo Alto, CA 94304-1395 

(650) 855-2203 

wsteeley@epri.com 

 

Thomas, Holly 

NREL 

1617 Cole Blvd. 

Golden, CO 80401-3393 

(303) 275-3755 

holly_thomas@nrel.gov 

Thompson, Chris 

Xantrex Technology Inc. 

8999 Nelson Way 

Burnaby, BC Canada V5A 4B5 

(604) 422-2500 

chris.thompson@xantrex.com 

Treanton, Bernard 

California Energy Commission 

1516 9th St., MS 43 

Sacramento, CA 95814-5504 

(916) 654-4512 

btreanto@energy.state.ca.us 

Vartanian, Charlie 

Southern California Edison 

1000 Portero Grande 

Monterey Park, CA 91755 

(323) 889-5516 

charles.vartanian@sce.com 

Vaughn, Amy 

NREL 

1617 Cole Blvd. 

Golden, CO 80401 

(303) 275-3863 

amy_vaughn@nrel.gov 

Venkataramanan, Giri 

University of Wisconsin 

1415 Engineering Drive 

Madison, WI 53706 

(608) 262-4479 

giri@engr.wisc.edu 

31 
Wallace, Ian Wang, Fred 

Eaton Corp., Innovation Center Virginia Tech 

4201 North 27th St. 645 Whittemore Hall (Mail Code 0179) 

Milwaukee, WI 53216-1897 Blacksburg, VA 240612 

(414) 449-6238 (540) 231-8915 

iantwallace@eaton.com fred.wang@vt.edu 

Wang, Warren Zolot, Matthew 

Navigant Consulting UQM Technologies Inc. 

One California Plaza, 300 S. Grand Ave. 

29th Floor 

7501 Miller Drive 

Frederick, CO 80530 

Los Angeles, CA 90071 (303) 278-2002 x1153 

(213) 670-3248 mzolot@uqm.com 

wwang@navigantconsulting.com 

32 
Appendix C. Speaker Biographies 

Imre Gyuk, U.S. Department of Energy 

Dr. Imre Gyuk is program manager of the U.S. Department of Energy’s Energy Storage and 

Power Electronics Research Program in the Office of Electricity Distribution and Energy 

Reliability. The program funds work on a variety of technologies, such as advanced batteries, 

flywheels, supercapacitors, and power electronics. The program works with California 

Energy Commission on a joint $9.6 million energy storage initiative. 

Forrest Small, Navigant 

Forrest Small is an associate director in the Energy Practice of Navigant Consulting. His 

professional focus is on the development and implementation of technology-based solutions 

for electric power delivery through work with utilities, equipment suppliers, and public sector 

agencies. Mr. Small has more than 15 years of experience in the electric power industry and 

has worked in consulting, open access transmission operations, transmission and distribution 

planning, and advanced power system engineering. 

Terry Ericsen, Office of Naval Research 

Terry Ericsen is the program manager for the ONR. He has led the development of the Power 

Electronic Building Block Program for the office. 

Fred Wang, Virginia Tech 

Dr. Fred Wang is an associate professor and the technical director at CPES, Virginia Tech. 

Prior to joining CPES five years ago, he worked for GE for 10 years as a power systems 

application engineer, a motor drive design engineer, and a power electronics R&D manager. 

His interests are power converters, power systems, and motor drives. 

Giri Venkataramanan, University of Wisconsin 

Giri Venkataramanan studied electrical engineering at Government College of Technology, 

Coimbatore, India; Caltech; and the University of Wisconsin, Madison. After teaching 

electrical engineering at Montana State University, Bozeman, he returned to the University of 

Wisconsin, Madison, as a faculty member in 1999, where he continues to direct research in 

various areas of electronic power conversion as an associate director of the Wisconsin 

Electric Machines and Power Electronics Consortium. He holds five U.S. patents and has coauthored more than a hundred technical publications. His interests are in the areas of 

microgrids, wind energy, power converter topologies, dynamics and control, and community 

engineering projects. 

33 
Ned Mohan, University of Minnesota 

Ned Mohan is Oscar A. Schott Professor of Power Electronics at the University of Minnesota 

in Minneapolis, Minnesota, where he has been teaching for the past 31 years. He has 

numerous patents and publications in the fields of power electronics, electric machines and 

drives, and power systems, in which he has written five books. 

John Mookken, SEMIKRON Inc. 

John Mookken’s career in power electronics began in 1999 as an applications and test 

engineer working on a U.S. Department of Energy-funded automotive power electronics 

program. In 2004, he joined SEMIKRON USA as a product manager for advanced integrated 

power modules. He is also the project director of the U.S. Department of Energy-funded 

AIPM program at SEMIKRON. He completed his MS in electrical engineering at the 

University of South Carolina. 

Ben Kroposki, NREL 

Ben Kroposki is the Distributed Energy Systems Integration supervisor at NREL. His 

expertise is in the design and testing of renewable and distributed power systems, and he has 

produced more than 40 publications in this area. Kroposki received his BS and MS in 

electrical engineering from Virginia Tech and is pursuing his Ph.D. in electrical engineering 

at Colorado School of Mines. He is a senior member of the IEEE and a registered 

professional engineer in Colorado. 

Ian Wallace, Eaton 

Ian Wallace is a senior specialist at Eaton Corp.’s Innovation Center, a research and 

development center in Milwaukee, Wisconsin. He has 16 years experience in electric power 

conversion designing and developing power electronics and control systems for industrial, 

aerospace, and power quality markets. 

Perry Schugart, American Superconductor 

Perry Schugart joined American Superconductor in December 2000 as director of Sales and 

Marketing of the company’s Power Electronics Business Unit. In this position, Schugart is 

responsible for the development, marketing, sales, and distribution of the company’s power 

electronic converter products. Prior to joining American Superconductor, Schugart held 

increasingly senior positions with International Rectifier, most recently as director of Sales 

Development. An Illinois native, Schugart holds a bachelor's of science degree in physics 

from the University of California, Santa Barbara. 

Matt Zolot, UQM 

Matt Zolot is a power electronics engineer at UQM, where he works on the development of 

modular inverter designs. Prior to working at UQM, Matt was with NREL, where he worked 

on power electronics for the transportation sector. Matt graduated from Georgia Tech with a 

BS in electrical engineering and is currently pursuing a master’s degree in electrical 

engineering at the Colorado School of Mines. 

34 
Alex Levran, Magnetek Inc. 

Alex Levran is the executive vice president and chief technology officer for Magnetek. He 

manages engineering activities in the design of power supplies, generators and motors, 

military and commercial power conversion, and alternative energy products. He also 

coordinates engineering activities in Europe and the United States, creates technology 

roadmaps, and engages in acquisitions. Prior to his work at Magnetek, he worked for Marlin 

Gernin and Teledyne. Levran has also been a visiting professor at the University of 

California, Los Angeles, and is currently on the board of directors for the Power Sources 

Manufacturers Association. 

Ray Hudson, Xantrex 

Ray Hudson is the vice president of Advanced Technology for Xantrex. 

Jonathan Lynch, Northern Power Systems 

In his role as chief technology officer of Northern Power, Mr. Lynch manages R&D and new 

product development efforts. Lynch is responsible for the identification and development of 

new technology and products to aid Northern’s growth across its business areas, which 

include products and services for remote industrial, onsite generation, and renewable-based 

power systems. Prior to joining Northern, Lynch was employed as a design engineer at 

Carrier Corp., where he modeled and designed high-performance refrigeration systems and 

controls for transportation applications. Lynch graduated from Stevens Institute of 

Technology with a BSME degree with honor. 

Kent Sheldon, SMA America 

Kent Sheldon has been involved in the renewable energy industry for 10 years with Kenetech 

Windpower, Trace Technologies, Xantrex Technologies, and SMA America. During this 

time, he has worked as a project engineer for a variety of three-phase, grid-tied photovoltaic 

and large hybrid power centers; an engineering manager for the PV Series inverter family; 

and, currently, as a sales support manager. 

35 
Appendix D. Workshop Presentations 

36 
Advanced Power Electronics Interfaces

for

Distributed Energy Workshop

August 24, 2006 

Energy Systems Integration Research Program

California Energy Commission

and

National Renewable Energy Laboratory

Mark Rawson

Energy Systems Integration Research Program

California Energy Commission

2

• Public Interest Energy Research (PIER)

– Established in 1996 as part of deregulation of electric utilities

– At least $62.5M collected annually from investor-owned utility ratepayers for 

"public interest" energy R&D

– Focuses on R&D not adequately provided by competitive and regulated 

markets

• Comprised of 7 research areas

– Environmentally Preferred Advanced Generation

– Renewable Generation

– Building End Use Efficiency

– Industrial, Agricultural and Water End Use Efficiency

– Environmental

– Transportation

– Energy Systems Integration

• New, complementary natural gas public interest program established in 

2005 that is expected to grow to $24M by 2009

California’s PIER Program

37
3

ESI uses systems engineering approach that requires looking at the big 

picture in a holistic fashion.

• Addressing T&D and load growth issues 

necessitates a coordinated effort

– Integrate EE, DR, DG-CHP, renewables 

(large and DG), and storage into local 

energy system designs

– Demonstrate the benefit to utilities, 

regulators and ratepayers

– Optimize integration strategies to target 

peak load and grid utilization

• Advances in the T&D system and on the load 

side can get us to this new vision for the 

future

– Sensors and monitoring

– Power electronics

– Communication and controls

– Intelligent automated systems

– Real time operations of the T&D system

ESI Approach

Science and technology can transform the 19th century electricity system 

into the 21st century information age if we dare to make it happen.

Distribution

Substation

Distribution

Transformer

Customers

Central Station 

Power Plant

Transmission 

Robust generation 

& transmission

Advanced

distribution is 

used to provide 

local reliability 

and flexibility, 

robustness of 

T&D and 

promote the use 

of demand 

response, CHP 

and renewable 

intermittent 

resources. Microgrid

Demand Response

Distribution 

Source: CERTS Microgrid

4

PIER 

Strategic 

Objectives

1. Enable optimal integration of renewables, distributed generation, 

demand response, and storage to the power system.

2. Improve capacity, utilization, and performance of transmission and 

distribution system. 

3. Improve cost and functionality of components to integrate demand

response, distributed generation, and electricity storage into the 

system. 

4. Improve security and reliability of electricity system. 

5. Support improvement of tariffs and regulations for demand response, 

distributed generation, storage, and renewables. 

6. Facilitate transmission siting process. 

7. Develop knowledge base for future decision-making and informed delivery, 

integration, and infrastructure policy relative to electricity. 

Integrated Electricity System that is Reliable and Secure

ESI Strategic Objectives Aligned with Policy Drivers

IEPR, EAP, California Solar Initiative, RPS all identify needs that ESI is 

focused on finding solutions for.

Our comprehensive portfolio of T, D, DR, DER Integration, Storage and 

Security research projects is supporting these strategic objectives.

Source: PIER 2007-2011 Electricity 

Research Investment Plan

38
5

Cost of Power Electronics

DER Capital Cost

$/kW

$900 - $1,800

Power Electronics

% of DER cost

Microturbine 35% - 45%

Wind Turbine $1,000 - $4000 25% - 40%

Fuel Cell $3,000 - $6,000 10% - 30%

Photovoltaics $6,000 - $10,000 10% - 25%

60%

80%

100%

20%

40%

0

Wind

Turbine Microturbine PV Fuel Cell

Power Electronics Other Capital Costs

Power electronics are part of DER total capital costs

key DER technologies, and 

represent a significant portion 

of the capital costs.

DER Type

Cost reductions in power 

electronics will reduce the overall 

cost of DER. Source: NREL

6

APEI Initiative is anticipated to be a collaborative ~$20M, 6 years effort.

Project Year 1 Year 2 Year 3 Year 4 Year 5 Year 6

Generation 1

Advanced 

Power 

Electronics 

Interface 

Build Prototype 

Version Build 

Commercial 

Version

Small Demo

Evaluate 

Performance

Large Demo

Generation 2

Advanced 

Power 

Electronics 

Interface

Build Prototype 

Version Build 

Commercial 

Version

Demo

Inputs from 

Topical 

Workshops

Topical 

Workshop on 

advanced 

components

Solicitation #1

Design of 

Generation 2

Solicitation #2

Evaluate 

Performance

APEI Initiative Timeline

39
7

Results from this workshop will help PIER and NREL structure our

strategies for the upcoming APEI Initiative.

Purpose

• To provide industry stakeholders with an update of the status of

technologies and issues in power electronics

Focus

• Development of advanced power electronic interfaces for Distributed 

Energy Applications

Purpose and Focus of Workshop

40
Power Electronics

for Utility Applications

at the Department of Energy

________________________________

IMRE GYUK, PROGRAM MANAGER

ENERGY STORAGE AND POWER ELECTRONICS 

RESEARCH, DOE CEC-PE 8-24-06

Office of Electricity Distribution 

and Energy Reliability

DOE

Utility Power Electronics funded 

through the Energy Storage Program 

but relevant for all Distributed Generation.

41
THE PQ PROBLEM:

• The Digital Economy is vulnerable to Power 

Quality (PQ) events such as micro-outages of a 

few milli-seconds and voltage sags of a few 

percent

• PQ events are common and cost the U.S. economy 

an estimated $52 billion

• System should be factory integrated and tested and 

allow plug and play installation

CBEMA Magnitude - Duration Scatter Plot (EPRI Data)

10-1 100 101 10 2 10 3 10 4

Voltage Magnitude (%)

175

150

125

100

75

50

25

0

Duration (60 Hz Cycles)

1.6 ms. 16 ms. 160 ms. 1.66 sec. 16.6 sec. 2.7 min.

Domain of Storage

42
• Full power must be available in 4 milliseconds = 

1/4 cycle for seamless power supply

• Energy should last for 15 -30 sec to cover 95% of 

outages and allow backup generation to ramp up

• Required development of a compact 250kW 

inverter (Omnion, S&C)

• Testing at PG&E facility. R&D 100

2 MW – 15 sec Mobile Battery System

43
10 MW - 30 sec System at AZ Microchip Plant 

S&C Power Conditioning System for a 

1.2 MW – 6 hour NaS System for Peak Shaving

44
SBIR Projects :

• Optically Isolated Inverter, (ONR co-funding)

R&D 100 Award

• High Current Inverter with Advanced Heat

Exchanger 

• Low Cost Modular Highly Reliable Inverter

Development of Emitter 

Turn-off (ETO) Switch

Need for a Switch that is 

Faster, More Powerful,

and Cheaper than 

Conventional Switches

45
GTO

Switching frequency (Hz)

50 500 5000

Power MW

5

15

45

IGBT

SCR

Target Region

ETO

1500

CURRENT HIGH-POWER SWITCH TECHNOLOGY

16 MW ETO Switch

• Developed at Virginia Tech – NC State

• 15-20 times faster than GTO

• 3 times the power and less expensive

than IGBT

• Development of Transmission

Stabilization Device Planned with TVA

46
Emitter Turn Off Thyristor

R&D 100 Award Winner

Transformerless STATCOM 

with Energy Storage

DOE, TVA, NC State University, 

EPRI, EPRI-Solutions, Sandia

To provide 4-quarter control with Real and 

Reactive Power

47
3-phase coupling 

transformer

Infinite Bus Load

PCC 69 kV 13.8 kV

Supercaps ETO-Based Converter

 Trailer housed close to 

customer

 Nominal 30 / 60 MVA 

2 second surge. 

 Energy storage: 15 MW, 

2 second active power

The BPA Wind Project:

 A 48 MW Wind Farm on the BPA Grid

 Extensive Complaints by other

Customers about poor PQ

 Proposed Solution by ETO Statcom

48
Condon Wind Voltage, July 14-Aug.14

5 minute samples

3-phase coupling 

transformer

Grid

34.5 kV PCC 69 kV

Supercaps ETO-Based Converter

 Condon, OR Wind Farm

 Weak grid

 Pronounced PQ issues

 10 MVA Statcom

 BPA, DOE, TVA, EPRI

48MW Wind Farm

Wind Integration

49
Specific Areas for Investment and

Management Attention – Plus ups

• Power electronics

• Superconductivity

• Solar energy utilization

• Buildings systems

• Complex systems 

assessment

FY 2008 Science, Technology, 

and Environment Briefing

• Electricity storage

• Carbon capture & storage

• Unconventional fossil

• Bioenergy

• Adaptive grid controls

Power Electronics and Advanced 

Materials

Through 2015

Near Term Options

< 2010

• ETO deployment

• Improved thermal 

management 

systems with novel 

materials • Advanced wide 

band gap systems 

deployment

• Nano-structured 

materials and 

devices

• Diamond switch

• Silicon carbide 

switch 

• High temperature 

materials

• Ionic fluids for 

electrolytes 

Through 2025 & beyond

50
SBIR Projects :

• High Power Densit y (100 kW) Silicon 

Carbide (SiC) Three Phase Inverters,

Arkansas Power Electronics (FY06)

• Advanced Power Converter System 

Using High Temperature, High Power Density

SiC Devices, Aegis Technology (FY06)

• Wide Band Gap, High Voltage, High

Frequency Switches (FY07)

Energy Storage and Power Electronics 

Program Peer Review

Nov. 2 – 3, 2006, Washington, DC

http://www. sandia.gov/ess/

51
1

DER Integration Research Program

Power Electronics Research Assessment

Executive Summary

Advanced Power Electronics Interfaces for DE Workshop

August 24, 2006

Public Interest Energy Research Program

California Energy Commission

2

Research Assessment Scope

• Objective

– To identify gaps in the research programs being conducted by government 

organizations and private industry in order to provide guidance to the PIER DER 

Integration Research Program as it develops its research agenda in the area of 

Power Electronics technologies used in DER applications.

• Scope

– Included the identification and assessment of research gaps in Power Electronics 

technologies used in DER applications. The analysis focused on Power 

Electronics technologies used in distributed generation systems (e.g., fuel cells, 

PV and microturbines) and distributed energy applications (e.g., inverters, 

uninterruptible power supplies and energy storage). 

– Included recommendations for specific research initiatives and approaches.

In 2004, the CEC asked NCI to provide input into the Distributed Energy 

Resources Integration research agenda for power electronics. 

Power Electronics Research Assessment Executive Summary, 08/24/2006

52
3

NCI recommended that the CEC support three research initiatives and act as 

a catalyst for a systems approach to power electronics. 

• Standardize the interface between power electronics systems and the grid

• Standardize and improve the interoperability of power electronics components and 

systems

• Improve the scalability and modularity of power electronic systems and 

components

CEC should drive for a systems approach:

• Large projects should include all stakeholders that develop the various components 

and systems rather than just the final integrator/packager of the technologies. 

• Smaller projects should be encouraged to exchange research needs ideas and 

results. These projects should be coordinated to effect the larger PE systems.

• CEC should begin by supporting the development of a forum to encourage a 

dialogue between different stakeholders. The initial topic could discuss how to move 

toward common standards and modularity.

Summary of Recommendations

Catalyst for Systems Approach

High Priority Research Initiatives

Power Electronics Research Assessment Executive Summary, 08/24/2006

4

Key Business Needs and Technology Challenges

The key business needs for DER power electronics are reducing costs 

and improving reliability. To support these an effective R&D program 

must address three technology challenges.

• Lack of standardization and the inter- and intra-operability of 

power electronic systems, components and the grid

• Need power electronic devices that are modular and scalable

• Need for improvements (R&D) in power electronic system 

packages

Key 

Business 

Needs

Technology 

Challenges

• Reduce costs – power electronics can account for up to 40% of 

the costs of a DER system

• Improve reliability – current level of performance may prevent the 

long term commercial penetration of DER using power electronics

Power Electronics Research Assessment Executive Summary, 08/24/2006

53
5

Key Research Initiatives 

The technology challenges can be overcome by supporting ten key 

research initiatives. 

1. Increase the efficiency of power electronic systems 

2. Standardize the interface between power electronics systems and the grid

3. Improve the thermal management characteristics of power electronic systems 

4. Minimize the harmonic distortions of power electronic systems

5. Improve the durability of power electronic systems and components

6. Reduce the complexity of power electronic systems

7. Improve the manufacturability of power electronic systems and components

8. Standardize and and improve the interoperability of power electronics components 

and systems

9. Improve the scalability / modularity of power electronic systems and components 

10. Minimize the system package size of power electronics

Power Electronics Research Assessment Executive Summary, 08/24/2006

6

Initiative Mapping

Initiatives that the CEC should consider are those that have a large 

technology gap, high public benefit and high DER applicability.

Significant gap

Moderate gap

Little or no gap

High

Research Initiatives

1. Increase the efficiency of power electronic 

systems 

2. Standardize the interface between power 

electronics systems and the grid 

3. Improve the thermal management 

characteristics of power electronic systems 

4. Minimize the harmonic distortions of power 

electronic systems

5. Improve the durability of power electronic 

systems and components

6. Reduce the complexity of power electronic 

systems

7. Improve the manufacturability of power 

electronic systems and components

8. Standardize and improve the interoperability 

of power electronics components and 

systems

9. Improve the scalability / modularity of power 

electronic systems and components 

10. Minimize the system package size of power 

electronics

Public 

Interest

Relative 

Distributed Energy Resources Impact 

and Applicability

Low

Low

High

Technology Gap

2

1

4

5

6

7

8 9

10

3

Power Electronics Research Assessment Executive Summary, 08/24/2006

54
7

Top Three Initiatives for the CEC

Of the ten research initiatives identified, three are the most attractive for 

the CEC: 

Standardize and improve the interoperability of power electronics components and systems

• A moderate research and funding gap exists, and this was raised as a critical issue for power electronics

• Private industry would likely have great difficulty organizing itself to address this challenge

• PIER could facilitate the bringing together of key stakeholders to develop interoperable components and 

systems

8

Improve the scalability / modularity of power electronic systems and components

• A significant research and funding gap exists

• This is initiative is very important for DER and moderately so for increasing public benefit

• The impact of this research initiative is cross-cutting as increased scalability and modularity should lead to 

improvements in the reliability and cost of DER power electronics

9

Standardize the interface between power electronics systems and the grid 

• A significant research and funding gap exists

• This initiative is very important for both DER and Public Benefit

• PIER could play an instrumental role in bringing together the key stakeholders to develop necessary and 

acceptable interface standards for DER power electronics

2

Power Electronics Research Assessment Executive Summary, 08/24/2006

8

End of Executive Summary

55
9

DER Power Electronics Context

A DER power electronics unit is a system that incorporates packaged 

devices and controls. The level of complexity depends on the application.

Device

1

Device

2

Device

3

System / Packaging

Grid

Generation

Source Load

Control

Control Control

DER Power Electronics Unit

10

Activity Areas

The power electronics activity can be classified into three fundamental 

areas: Devices, System / Packaging, and Controls.

Devices

• The discrete switching 

devices themselves

• Current technology is 

silicon-based, with siliconcarbide technology the 

most likely successor in 

the coming years.

System / Packaging

• The arrangement of 

devices

• Devices can be can be 

used individually or in 

combinations depending 

on the application

Controls

• Hardware and software to 

manage the power 

electronics system as well 

as monitor and respond to 

changing conditions

Description

Examples

• Metal Oxide 

Semiconductor Field Effect 

Transistor (MOSFET)

• Insulated Gate Bipolar 

Transistor (IGBT)

• Gate Turn-Off Thyristor 

(GTO)

• Rectifier

• Inverter

• Converter

• Sensors

• Processors

• Communications

• Software

Current R&D

Devices:

• IGCT switch

• Super GTO switch

• ETO switch

Materials

• Silicon Carbide

• Diamond 

• ETO

• Advanced topologies 

utilizing higher 

voltage/capacity devices

• Thermal management

• Packaging

• Plug and play 

interconnection of DER

• Autonomous control

• Peer to peer 

communications

56
11

Research Gap Analysis Gap Terminology

The degree to which individual research initiatives are currently being 

pursued was categorized based on comments and feedback.

• Significant gap: Few companies or entities are adequately pursuing this strategy 

at a level that will likely ensure the strategy has a reasonable chance of success to 

help resolve the issue it is addressing. This could indicate an area that has been 

overlooked or just emerging as a viable strategy. 

• Moderate gap: There are several companies and/or entities pursuing this strategy. 

Continued and additional activity is likely required to ensure the strategy has a 

reasonable chance of success to help resolve the issues it is addressing. 

Strategies were also given a moderate gap rating if it is deemed a strategy that is 

not appropriate or feasible to pursue at this time.

• Little or no gap: There are many companies and/or entities pursuing this strategy. 

The current level of activity is likely appropriate to ensure the strategy has a 

reasonable chance of success to help resolve the issue it is addressing. Little 

additional work beyond what is currently funded is needed.

12

Research Gap Analysis Research Initiative 1

Increase the efficiency of power electronic systems

Increasing the efficiency of power electronic systems is a key concern given its impact on the effectiveness of power 

electronics solutions, and there are multiple projects currently underway that are addressing this issue. Nevertheless, 

given the fundamental importance of this top, additional support may be warranted. 

Research Initiative 1

1

Significant gap Moderate gap Little or no gap

Public benefit: This initiative could provide a competitive advantage, but benefits are primarily to the manufacturer.

Relative DER Applicability: This initiative is a crosscutting issue, but there is little room left for economic or reliability improvements to 

occur as a result of increased efficiency. 

C

Compact Diode-Clamped Multilevel Converter. Improve 

reliability and efficiency by developing a diode-clamped 

multilevel inverter that share a common DC bus

H

Silicon Carbide Power Electronics for Utility Application. 

Improve the reliability of power electronics by researching 

the benefits and applications of SiC. 

L

Digital Control of PWM Converters. Improve reliability by minimizing the 

power dissipation of the converter by dynamically adjusting parameters such 

as the synchronous rectification dead time and the current sharing in multiphase converters.

O Diamond Tip Emitters. Improve the reliability and efficiency of power 

electronics through the use of diamond tipped emitters 

A

Optically Isolated 5MW Inverter. Improve reliability by 

developing a new, highly efficient (99%+) inverter design 

that utilizes optical sensing and control, DSP control 

algorithms and HVIGBT devices. 

Research Projects That Address Initiative

Estimated Total Funding Needed $20 M Estimated Current Public Support $1.9 M

J

High Reliability Inverter Development. Reduce the cost and improve 

reliability by developing an inverter that operates like a convention 

hard-switched inverter with no limitations on switching timings or 

additional control complexity.

2.5

2

57
13

Research Gap Analysis Research Initiative 2

2 Standardize the interface between power electronics systems and the grid

Standardization of a power electronic grid interface for DER is critical to increasing the penetration of DER. Several 

projects are developing technology that will support this initiative, but only one project directly addresses the issue of 

standardization. Moreover, the current public support is a small fraction of the estimated total funding required.

Research Initiative 2

Significant gap Moderate gap Little or no gap

Public benefit: Very limited incentives, and all classes of stakeholder (including ratepayers) will benefit. 

Relative DER Applicability: This initiative is unique to DER and there could be a significant impact to DER through reduced installation 

costs and improved reliability.

Research Projects That Address Initiative

$15 M $1.5 M

G Distributed Energy Interface. Improve the reliability of power electronics by improving the power flow between energy resources and the 

grid through the use of power electronic interfaces. 

N ETO Thyristor Development. Reduce cost and improve reliability by utilizing integrated power electronic modules composed of 

standardized components (instead of custom designed systems) in the development of ETO Thyristors. 

J High Reliability Inverter Development. Reduce the cost and improve reliability by developing an inverter that operates like a conventional 

hard-switched inverter with no limitations on switching timings or additional control complexity.

C Compact Diode-Clamped Multilevel Converter. Improve reliability by developing a diode-clamped multilevel inverter that share a common 

DC bus Their unique structure allows them to span high voltage without the use of transformers and with no voltage sharing problems. 

V Static Inverter Type Testing. Improve reliability by developing a procedure type and verification testing of static inverter. 

4.5

4.5

Estimated Total Funding Needed Estimated Current Public Support 

14

Research Gap Analysis Research Initiative 3

Research Initiative 3

Significant gap Moderate gap Little or no gap

Public benefit: This initiative is more of a product attribute, and the benefits are not widespread. 

Relative DER Applicability: This initiative could reduce package size and manufacturing costs. Reliability is increased through the 

reduction in failures associated with poor thermal management.

Research Projects That Address Initiative

$10 M $2 M

3 Improve the thermal management characteristics of power electronic systems

There are only a few projects addressing the thermal management issue, yet this is a major issue surrounding power 

electronics. Several of the people interviewed raised this topic as an area requiring further research. Thermal 

management can be controlled or improved through both material and mechanical advances and should increase both 

performance and reliability. 

H Silicon Carbide Power Electronics for Utility Application. Improve the reliability of power electronics by researching the benefits and 

applications of SiC. 

R Thermal Management for Power Electronics. Increase the reliability of power electronics by improving the thermal characteristics with a 

combination of high--temperature materials and advanced cooling strategies

2.5

1.5

O Diamond Tip Emitters. Improve the reliability and efficiency of power electronics through the use of diamond tipped emitters 

Estimated Total Funding Needed Estimated Current Public Support 

58
15

Research Gap Analysis Research Initiative 4

Research Initiative 4

Significant gap Moderate gap Little or no gap

Public benefit: There is significant public interest and multiple stakeholder classes will benefit.

Relative DER Applicability: There is minimal impact on DER applications. 

Research Projects That Address Initiative

$2 M $0.5 M

D Multilevel Universal Power Conditioner. Improve the reliability of power electronics through the development of a multilevel universal 

power conditioner. 

Minimize the harmonic distortions of power electronic systems

There was only one project identified that is focusing on reducing the harmonic distortions of power electronics, yet a 

significant amount of research has been done in this area in the past. Industry standards already exist to address this 

issue.

4

I Harmonic Elimination Technique and Multilevel Converters: Control a multilevel inverter in such a way that it is an efficient, low total 

harmonic distortion (THD) inverter that can be used to interface distributed dc energy sources to a main ac grid.

2

5

Estimated Total Funding Needed Estimated Current Public Support 

16

Research Gap Analysis Research Initiative 5

Research Initiative 5

Significant gap Moderate gap Little or no gap

Research Projects That Address Initiative

$20 M <$0.5 M

5 Improve the durability of power electronic systems and components

A significant research gap exists as relatively few projects are actively concentrating on increasing the durability of power 

electronic components and systems. While power electronics system manufacturers are likely to be actively conducting 

internal research to improve the reliability of their products, a more systemic approach with public funding support may 

yield benefits that can be shared industry-wide.

None

Public benefit: This initiative benefits primarily manufacturer and customer.

Relative DER Applicability: This initiative has high applicability to DER, and improves reliability. 4

2

Estimated Total Funding Needed Estimated Current Public Support 

59
17

Research Gap Analysis Research Initiative 6

Research Initiative 6

Significant gap Moderate gap Little or no gap

Research Projects That Address Initiative

$10 M $2.0 M

6 Reduce the complexity of power electronic systems

The DOE is funding several research projects to reduce the complexity of power electronics, but many comments were 

raised about the significance of this issue. This is a cross-cutting issue that will help reduce costs, ease manufacturing, 

and facilitate standardization.

F

Soft Switching Snubber Inverter. Reduce the cost and 

improve reliability through the development of advanced 

inverter designs that utilize fewer components and 

modular electronics.

J

High Reliability Inverter Development. Reduce the cost 

and improve reliability by developing an inverter that 

operates like a convention hard-switched inverter with no 

limitations on switching timings or additional control 

complexity.

N

ETO Thyristor Development. Reduce cost and improve reliability 

by utilizing integrated power electronic modules composed of 

standardized components (instead of custom designed systems) 

in the development of ETO Thyristors. 

M

PV Inverter Products Manufacturing and Design 

Improvement. Design a large number of products based 

on small number of functional modules to achieve high 

manufacturing efficiencies and enhanced product 

reliability 

P

Standard Power Electronic Interfaces. Reduce the cost and 

improve the reliability of power electronics by developing 

standardized approaches for integrating power converter 

components.

Public benefit: Commercial incentives already exist, and this initiative primarily benefits the manufacturer.

Relative DER Applicability: This initiative is very applicable to DER and significant cost reductions could occur. 4.5

1

O Diamond Tip Emitters. Improve the reliability and efficiency of power 

electronics through the use of diamond tipped emitters 

Estimated Total Funding Needed Estimated Current Public Support 

18

Research Gap Analysis Research Initiative 7

Research Initiative 7

Significant gap Moderate gap Little or no gap

Research Projects That Address Initiative

$15 M $1.2 M

Improve the manufacturability of power electronic systems and components

There is a need for additional research to improve ease of manufacturing. Although the DOE is supporting projects 

focused on reducing manufacturing costs, there is still a great deal of research needed. Manufacturing costs are a major 

part of total power electronic system costs, and so improving the ease of which a component is manufactured could have 

a substantial impact on the attractiveness of power electronics based DER. 

7

P Standard Power Electronic Interfaces. Reduce the cost and improve the reliability of power electronics by developing standardized 

approaches for integrating power converter components.

N ETO Thyristor Development. Reduce cost and improve reliability by utilizing integrated power electronic modules composed of 

standardized components (instead of custom designed systems) in the development of ETO Thyristors. 

M PV Inverter Products Manufacturing and Design Improvement. Design a large number of products based on small number of functional 

modules to achieve high manufacturing efficiencies and enhanced product reliability 

J High Reliability Inverter Development. Reduce the cost and improve reliability by developing an inverter that operates like a convention 

hard-switched inverter with no limitations on switching timings or additional control complexity.

B Cascade Multilevel Inverter for Utility Applications. Reduce the manufacturing cost and improve reliability and efficiency of multilevel 

inverter through the utilization of modular and compact circuit topology 

Public benefit: Commercial incentives exist, and this initiative primarily benefits the manufacturer.

Relative DER Applicability: This initiative is very applicable to DER and significant manufacturing cost reductions could occur. 4.5

1

Estimated Total Funding Needed Estimated Current Public Support 

60
19

Research Gap Analysis Research Initiative 8

Research Initiative 8

Significant gap Moderate gap Little or no gap

Research Projects That Address Initiative

$5 M $1.0 M

8 Standardize and and improve the interoperability of power electronics components and systems

Standardization of interfaces was identified as a significant barrier surrounding power electronics. There are public and 

privately funded projects addressing the standardization / interoperability issue, but research is still needed.

N ETO Thyristor Development. Reduce cost and improve reliability by utilizing integrated power electronic modules composed of 

standardized components (instead of custom designed systems) in the development of ETO Thyristors. 

J High Reliability Inverter Development. Reduce the cost and improve reliability by developing an inverter that operates like a conventional 

hard-switched inverter with no limitations on switching timings or additional control complexity.

C Compact Diode-Clamped Multilevel Converter. Improve reliability by developing a diode-clamped multilevel inverter that share a common 

DC bus Their unique structure allows them to span high voltage without the use of transformers and with no voltage sharing problems. 

Public benefit: Limited incentives exist, and this initiative could benefit multiple stakeholders.

Relative DER Applicability: This is a crosscutting initiative that could yield significant cost and reliability benefits. 4

3

Estimated Total Funding Needed Estimated Current Public Support 

20

Research Gap Analysis Research Initiative 9

Research Initiative 9

Significant gap Moderate gap Little or no gap

Research Projects That Address Initiative

$10 M $1.3 M

9 Improve the modularity / scalability of power electronic systems and components 

Scalability and modularity were identified as major barriers to improved adoption of power electronics based systems due 

to the potential impact on flexibility and cost. There are few projects addressing these issues and significant research is 

still needed.

Q New Power Electronic Technologies. Reduce costs and improve reliability by developing power electronics products using cutting edge 

technology. 

J High Reliability Inverter Development. Reduce the cost and improve reliability by developing an inverter that operates like a convention 

hard-switched inverter with no limitations on switching timings or additional control complexity.

P Standard Power Electronic Interfaces. Reduce the cost and improve the reliability of power electronics by developing standardized 

approaches for integrating power converter components.

Public benefit: Limited incentives exist, and this initiative could benefit multiple stakeholders.

Relative DER Applicability: This initiative is highly applicable to DER and could yield significant cost benefits. 4.5

3

Estimated Total Funding Needed Estimated Current Public Support 

61
21

Research Gap Analysis Research Initiative 10

Research Initiative 10

Significant gap Moderate gap Little or no gap

Research Projects That Address Initiative

$5 M $0.8 M

Minimize the system package size of power electronics

A moderate research gap exists as several projects identified are trying to minimize the system footprint, and this topic of 

obvious concern to manufacturers. The size of the power electronics package impacts the attractiveness of DER 

technologies and the ease of integration.

10

NOTE ON MANUFACTURERS: Given that many of the research initiatives are manufacturing or packaging related, it is likely that many DER power 

electronics equipment suppliers are actively pursuing internally-funded research supporting many of the research initiatives identified well beyond 

research activities co-funded by public sector entities. However, due to competitive nature of the business, very little is known about these internal

research activities.

B Cascade Multilevel Inverter for Utility Applications. Reduce the manufacturing cost and improve reliability and efficiency of multilevel 

inverter through the utilization of modular and compact circuit topology 

A Optically Isolated 5MW Inverter. Improve reliability by developing a new, highly efficient (99%+) inverter design that utilizes optical 

sensing and control, DSP control algorithms and HVIGBT devices. 

Public benefit: Limited incentives exist, yet this initiative benefits the manufacturer and customer only.

Relative DER Applicability: This initiative has limited applicability to DER and could actually increase costs. 1.5

2.5

Estimated Total Funding Needed Estimated Current Public Support 

22

• Literature search of projects and activities by various stakeholders 

– DOE and National Labs

– State based R&D funding entities (e.g., CEC, NYSERDA, etc.)

– Universities

– Manufacturers

– Industry organizations and standards bodies

Literature Search and Interviews

The first stage of this project was to conduct literature searches and 

telephone interviews with research stakeholders.

– Alex Huang of Virginia Tech

– Giri Venkataramanan of University of Wisconsin

– Keith White and Richard Zhang of GE

– Leon Tolbert of Oak Ridge National Laboratory 

and the University of Tennessee 

– Matt Lazarewicz of Beacon Power

– Nag Patibandla of NYSERDA

– Stan Atcitty of Sandia National Laboratory

– Tim Zgonena of UL

– Bill Erdman of DUA

– Ben Koproski of NREL

– Bob Panora of Tecogen

– Greg Ball of PowerLight

– Ian Wallace of Eaton

– Jim Davidson of Vanderbilt University

– Perry Schugart of American Superconductor

– Scott Samuelsen of UCI

– Syed Ahmed of Southern California Edison

• Telephone interviews with stakeholders and researchers such as:

62
Advanced Electric 

Power Systems Thrust

Power Electronic Building Blocks, 

PEBB

ONR Experience and Observations 

Terry S Ericsen

Program Office for Electrical Science and Technology

Office of Naval Research

ericset@onr.navy.mil

Advanced Electric 

Power Systems Thrust

Recent Innovations

• Computing Power Increase

• High-Speed and Low-Cost Controllers

• System Simplifying Concepts 

63
Advanced Electric 

Power Systems Thrust

“System of Systems” Design 

Challenges

Today

• Rule Based Design

• Standard Parts

• Increasing Complexity 

• Specifications, Documents

• Small Samples Statistics

Tomorrow

• Relational Based Design

• Standard Processes 

• Increasing Detail

• Model is the Specification

• Physics Based Analysis

• Statistics from All of 

Industry

Advanced Electric 

Power Systems Thrust

The Changing Role of Simulation

• Today, simulation is used for evaluation 

-- Analysis.

– Simulation programs require detailed 

design information

• Circuit parameters are entered before 

simulation begins.

• Variations in design can be analyzed 

• Tomorrow, simulation will become part 

of the design process -- Synthesis.

The Model Will Be The Specification

64
Advanced Electric 

Power Systems Thrust Future Design Process

Reality Modeling Simulation

Specs Design through

Simulation Reality

Today

Tomorrow

Roger Dougal & Antonello Monti, University of South Carolina

Advanced Electric 

Power Systems Thrust The Design Cycle

Customer Designer Customer Designer

Supplier Designer Supplier Designer

Mission: Mission: 

Performance, Life, & Performance, Life, & 

Cost 

Products Requirements

65
Advanced Electric 

Power Systems Thrust

Changing World of Models --

Dynamics

• Model is the Specification

• Model is the Control

• Model is the Machine

Advanced Electric 

Power Systems Thrust

Physics-Based Models are Required

• Product models must be specific

• Requirement models can be general

– In fact, requirement models with very 

specific details, in the design phase, can 

lead to an overly constrained problem.

66
Advanced Electric 

Power Systems Thrust Complexity

(From “Modeling and Simulation in System Engineering: Whither Simulation Based 

Acquisition?” By Andrew P. Sage and Stephen R. Olson, George Mason University)

• The more identical that a model must be to the actual system to 

yield predictable results, the more complex the system is. 

• Complex systems “...have emergence ... the behavior of a 

system is different from the aggregate behavior of the parts and

knowledge of the behavior of the parts will not allow us to 

predict the behavior of the whole system.”

• “In systems that are ‘complex,’ structure and control emanate 

or grow from the bottom up.”

• A system may have an enormous number of parts, but if these 

parts “interact only in a known, designed, and structured 

fashion, the system is not complex, although it may be big.”

• Although a physical system maybe not be complex, if humans 

are a part of the system, it becomes complex

Advanced Electric 

Power Systems Thrust

Complexity and Simplification

• Complex systems can be simplified by: 

– Physics-based partitioning

• Based on the nature of the materials, components, and 

manufacturing methods

– Adding intelligent active devices

– Creating controlled and predictable system-states at 

physics-based partitions

• All of this increases detail, size, weight, and cost.

• Therefore:

– The size, weight, and cost of these technologies have to be 

reduced to enable practical application and simplification.

– Computational abilities and new modeling and simulation 

tools are needed to allow for design with increased detail.

67
Advanced Electric 

Power Systems Thrust

Development Processes

$

Performance

(Power Density, Specific Power, Reliability, and etc.)

Commercial Aerospace

Assumptions:

1) Conservative

2) Minimum 

Entropy 

Production

Advanced Electric 

Power Systems Thrust

Technology Maturity Based on the MicroEvolution of Biological Systems

Performance

Existing

Technologies

S -- Curve

New

Technologies

S -- Curve

Time

Michael S. Slocum, “Technology Maturity Using S-curve Descriptors,”

Proceedings of the Altshuller Institute TRIZCON99 

68
Advanced Electric 

Power Systems Thrust Management Influences

Development

Influence

Concept Demonstration Product

Modeling and Simulation as Early as Possible in a Project

Advanced Electric 

Power Systems Thrust

Example: The Electrical System and

The Power Electronics Thesis

• Present electrical power systems are complex.

– At equilibrium, 60Hz. Supplies power to 60Hz loads the 

system is stable and predictable.

– If perturbed, the system can become unstable and 

unpredictable – bifurcation can occur. 

– Humans are needed to operate the system

• Future PEBB based power electronic systems 

will not be complex.

– Automation is possible -- reduced operating costs

– Progressive integration -- reduced system costs

– Higher availability due to physics-based health prediction –

reduced maintenance costs

– Increased reliability and life by controlling overstresses

69
Advanced Electric 

Power Systems Thrust

Modularization/Integration

Process: CPES Example

Partition

• Optimization techniques

• Spatial and functional, 

then temporal

• Facilitate manufacturing, 

achieve volume

Integration

• Interaction of components: 

energy, control 

• Spatial, then temporal and 

functional

• Manufacturing volume

Non-desired interactions are non-desired, non-useful, 

energy exchanges among system components

System Modules

Partition

Integration

Optimization

Dushan Boroyevich, VA Tech

Advanced Electric 

Power Systems Thrust

Assemblies

Machines

Systems

ONR Ships Initiated, S3D

Time resolution

(more information)

Physical Process Resolution

(more information)

0-D 1-D 2-D 3-D

Lumped parameters Distributed 

parameters

Static

AC Steady-state

Switching average

Switching detail

Computational

Design Challenges,

Partitions and Standard Interfaces 

Time resolution

(more information)

Physical Process Resolution

(more information)

0-D 1-D 2-D 3-D

Lumped parameters Distributed 

parameters

Static

AC Steady-state

Switching average

Switching detail

Computational

Time resolution

(more information)

Physical Process Resolution

(more information)

0-D 1-D 2-D 3-D

Lumped parameters Distributed 

parameters

Static

AC Steady-state

Switching average

Switching detail

Computational

Time resolution

(more information)

Physical Process Resolution

(more information)

0-D 1-D 2-D 3-D

Lumped parameters Distributed 

parameters

Static

AC Steady-state

Switching average

Switching detail

Computational

Time resolution

(more information)

Physical Process Resolution

(more information)

0-D 1-D 2-D 3-D

Lumped parameters Distributed 

parameters

Static

AC Steady-state

Switching average

Switching detail

Computational

Ill Posed:

• A set of technologies can yield many different systems

• A system can have many different sets of technical solutions

Materials

Components

70
Advanced Electric 

Power Systems ThrustTraditional Power Electronics Industry

Advanced Electric 

Power Systems Thrust

PEBB Based Power Electronics Industry

71
Advanced Electric 

Power Systems Thrust

Asynchronous Processes for Multiplicative Product 

Development -- Concurrent Engineering

Advanced Electric 

Power Systems Thrust

Makes the electrical 

conversion needed via 

software programming

(Embedded Agents)

Senses what 

they are 

plugged into... 

Senses what is 

plugged into 

them... 

Controls

I/O I/O

Thermal

PEBB

Industry Standards Initiated

Functions In Software

Inverter

Breakers

Frequency Converter

Motor Controller

Power Supply

Actuator Controller

filter

filter

Power Switching

PEBB -- A Simple Set of Blocks

for Power System Development (Functional)

• PEBB defined by IEEE 

(Power Engineering Society)

• WG I8

• TF2, PEBB Technologies

72
Advanced Electric 

Power Systems Thrust

Universal Control Architecture for Control 

Interfaces (temporal) , IEEE Guide Initiated

PEBB Concept for Power Electronics

Advanced Electric 

Power Systems Thrust

Thermal system

Hydraulic system Mechanical system Electrical system Thermal system

Mechanical system

Motor

Generator

Pump

Ambient

Circuit Breaker

Motor Controller

Plumbing Fluid Impeller Shaft Rotor Stator Cable

Current

sense

& arc

dynamics

Stator

Actuator

Armature

Power

Electronics Cable

Rotor Engine

Cable

Heat sink

to ambient

Heat

Generation

Heat

SinkConduction

Shaft

Real PEBB

systems are

multi-technical

VTB Simulation Environment

Roger Dougal

73
Advanced Electric 

Power Systems Thrust

Validation, Emulation, and 

Incremental Prototyping

• Validation of models 

– Controller In the Loop

– Processor In the Loop

– Hardware In the Loop

• Real-time simulation is needed for real 

hardware

• High speed real-time simulation is need for 

high-speed controllers

• Multi-rate simulation for distributed simulation 

environments

Advanced Electric 

Power Systems Thrust PEBB Examples

Virginia Tech Universal 

Controller

ABB Lopak5 IGBT based 

PEBB with 12 capacitor DC 

bank

ABB ANPC IGCT PEBB 

(16 MVA PowerStack)

74
Advanced Electric 

Power Systems Thrust

PEBB Applications

American 

Superconducto

r PEBB 

products

Solid State Transfer 

Switches and 

Current Interrupters 

by L-3 Power 

Paragon Inc.

ABB Medium Voltage 

ABB DVR (Dynamic Propulsion Drive

Voltage Restorer)Two 

units, 22 MVA each

ABB, 40 MW Energy Storage 

Applications

Advanced Electric 

Power Systems Thrust

Active Rectifier

DC-DC

AC Voltage Source

Motor Control

Pre-charge

Control

Interface

Application

Module Control

Strategy

DSP

A

Power Processor

Gate Driver

DSP

B

Fiber Optic I/O

Power Pole 1 Power Pole 2 Power Pole 3

I/O & Communication 

Interface 

Embedded

Controller

& Control Interface

Power

Supply

PowerModule 

Asynchronous 

Serial Terminal 

Adapter 

Serial 

Port 

Connector

Fiber

System

Hardware

Interface

PM1000 Developers Kit

75
Advanced Electric 

Power Systems Thrust

Rapid Product Development Benefits

Production

System Integration

Iteration

S/W Development

H/W Development

S/W Design

H/W Design

System Design

t = 0

American

Superconductor

PM1000

Typical OEM

In-house

Development

1 m .25 m

1 m 1 m

2 m .25 m

3 m .25 m

2 m 0

2.5 m 0

1.5 m 0

1.5 m 1 m

14.5 m 2.75 m 2 4 6 8 10 12 14

Months

Gained Advantage ($)

15

Labor & Overhead

Materials

Testing

$100,000 $10,000

$100,000 0

$2,375,000 $422,500

$2,175,000 $412,500

Product Dev. Time

Product Dev. Cost

PEBB concept leads to a 5 times 

reduction in design cost!

Advanced Electric 

Power Systems Thrust

Simple APF Hardware Test Bed

Si

Ri

T

i uT

uS

uR

u i Sh i Th i Rh i

L L L

PM1000

PEBB

Motorolla

DSP

based

controller

C

Shunt Connected Current Controller

Supply

DC Drive

PC

1) Power supply, 208V, 60A

2) 6RA70 thyristor control 

rectifier (TCR) from 

SIEMENS

3) PM1000 PEBB

4) DSP56F807 based 

Controller

Herbert L. Ginn III

76
Advanced Electric 

Power Systems Thrust

Shunt Current Controller Applications

Herbert L. Ginn III

Advanced Electric 

Power Systems Thrust Generalization of ShCC Digital Controller 

Model in VTB

• Updating of the VTB ShCC controller 

model is carried out at regular intervals

Herbert L. Ginn III

77
Advanced Electric 

Power Systems Thrust

Vehicle Power Problem

dt

dw p = ε

w = energy which is equal to the ceiling 

amount of the installed generation 

capacity (may increase over time with 

technology – fractionally)

p, power requirements are increasing 

multiplicatively by 10x to 100x

Conditions:

1) Size, weight, cost stay the same or decrease

2) Open architecture, plug and play

ε = efficiency

Advanced Electric 

Power Systems Thrust

Notional Integrated Power System (IPS)

78
Advanced Electric 

Power Systems Thrust

Architectural Transformation

Rolls-Royce/

ABB/ESRDC

Eliminate Charging Circuit

Electrical Zone No. 2

Advanced Electric 

Power Systems Thrust

Life of the Ship

(Ship Alts. & upgrades)

SHIP

DELIVERY

Future Vision of Shipboard Electrical Design oard Electrical Design 

Development Process Development Process

TRAINING TESTING CONSTRUCTION

CONCEPT PRELIMINARY CONTRACT

(DETAIL)

MODELING AND 

SIMULATION 

Prototype Design 

Verification & 

Validation

Digital Control & 

Real-time 

Simulation

MODEL IS THE SPECIFICATION

MODEL-BASED DEVELOPMENT PROCESS

Moni Islam, Northrop Grumman

79
Advanced Electric 

Power Systems Thrust

Needs Continued – Social Structure

• Modeling Standards

• Benchmark Models

• Public Library of Models

• A body of international volunteer 

experts for all of the above

• And ...

80
August 24, 2006

Center for Power Electronics Systems

A National Science Foundation Engineering Research Center

Virginia Tech, University of Wisconsin - Madison, Rensselaer Polytechnic Institute

North Carolina A&T State University, University of Puerto Rico - Mayaguez

Integrated Power Electronics Building Block 

Modules, Converters, and Systems

Fred Wang

Virginia Tech, Blacksburg, VA

fred.wang@vt.edu

Advanced Power Electronics Interfaces for DE Workshop

Sacramento, CA, USA

August 24, 2006 1

Distributed Energy Resources

• Wind

• Bio

• Microturbines

• Others 

Power Electronics Interface a Key Enabling Technology 

• Lower cost

• Higher reliability

• Better performance

• Solar

• Fuel cells

• Energy storage

81
August 24, 2006 2

Improving DE Power Improving DE Power Electronics Interfaces

• Conventional approach

– components, circuits, control, processes, design 

optimization 

• Modular building blocks

– high volume, standardization 

• Integration

– reliability, performance, manufacturing 

• System 

– added functionality and values 

CPES focus on IPEMs and IPEM building 

blocks based systems 

August 24, 2006 3

Over 80 Industry Partners

Only ERC in Power Electronics

VT – the Lead Institution

Virginia Tech

University

of Wisconsin

Madison

Rensselaer

Polytechnic

Institute

University

of Puerto Rico

Mayaguez

North

Carolina A&T State

University

Virginia Tech

System

Integration

IPEM

Center for Power Electronics Systems

A National Science Foundation Engineering Research Center

82
August 24, 2006 4

CPES Research Vision and Objectives CPES Research Vision and Objectives

– Power electronics to follow microelectronics Power electronics to follow microelectronics –

Power Processing IPEM

• Integrated Power Electronics 

Modules (Standardized 

building blocks)

• Reduce labor content

• Low cost

1960 1970 1980 1990 2000 year

Market ($)

1 T

Signal 

Processing

IC

• Standardization

• Manufacturability

• Volume 

production

• Cost reduction

Moore’s Law Prevails

August 24, 2006 5

Vision and Focus

IPEM Concept:

A concept for design of electronic energy processing 

systems with improved performance, reliability, 

manufacturability, and reduced cost, based on the 

integration of a set of building blocks with:

• Integrated functionality,

• Standardized interfaces,

• Suitability for mass production, and

• Application versatility.

Enable dramatic improvements in the performance, 

reliability, and cost-effectiveness of energy processing 

systems by developing an integrated system approach via

Integrated Power Electronics Modules (IPEMs).

83
August 24, 2006 6

PM

Machine 

Rotor

Modular

Pole-Drive

Units

Discrete converter Integrated converter

• Power Distribution Converters:

• EMI Filter IPEM

• Active IPEM

• Passive IPEM

Different Approaches to Integration

• Integrated Source Converters?

– Low-cost, “intelligent motors”

• motor as output filter

Motor and 

Converter 

Integration 

Standard-Cell

IPEMs:

Microprocessor

and Converter 

Integration

– Fast power delivery to microprocessors

• minimum distance to load

• Integrated Load Converters:

August 24, 2006 7

CPES Research Thrusts

Engineered

Systems

Enabling

Technology

Fundamental

Knowledge

Advanced 

Power 

Semiconductors

(APS)

T. P. Chow, RPI

Integratable

Materials

(IM)

G. Q. Lu, VT

High-Density

Integration

(HDI)

J. D. van Wyk, VT

ThermoMechanical

Integration

(TMI)

E. P. Scott, VT

Control

& Sensor

Integration

(CSI)

R.D.Lorenz, UW-M

IPEM-Based

Power Conversion Systems

(IPEM-PCS)

D. Boroyevich, VT

Electro-Magneto-Thermo-Mechanical Integration Technology (EMTMIT)

T. M. Jahns, UW-M

Microprocessor

and Converter

Integration

Microprocessor

and Converter Standard-Cell

Active IPEMs

Standard-Cell

Active IPEMs

Standard-Cell

Passive and Filter

IPEMs

Standard-Cell

Passive and Filter

IPEMs

Motor and

Converter

Integration

Motor and

Converter

Integration

84
August 24, 2006 8

Promoting IPEMs

For Different Power Ranges and Applications

CPES industry consortium members or research sponsors

IR, Philips, On Semi,

Intersil, Linear Tech,

TI, Renesas, NSC,

Power One, Infineon,

ST, Maxim, Micrel,

Volterra, Primarion, 

Fairchild, Analog

10-100 W IPEMs

CPES Monolithic 

VRM

IR iPOWIRTM

Philips PIP20x

TI SWIFTTM

PMOS1

PMOS2

NMOS1

NMOS2

Driver1

Driver2

Controller

PMOS1

PMOS2

NMOS1

NMOS2

Driver1

Driver2

Controller

ONR, DOE, NSWC, Thales, Northrop 

Grumman, Rockwell Automation,

General Dynamics, ABB, Bettis, Alstom,

ACI, PEMCO, TVA

CPES 800 V, 40 A 

ZVZCT phase-leg

10 kW - 10 MW IPEMs

1.8 kV, 60 A, 3-level 

ZVZCT phase-leg

CPES

4.5 kV, 4 kA ETO

ABB, Hitachi, IXYS, Toshiba, Semikron, Fuji,

Infineon, Eupec, Powerex

1-10 kW IPEMs

Semikron IPM

CPES Active 

IPEM

CPES Flip-ChipOn-Flex Phase-LegCPES Transmission 

Line Filter

CPES Passive IPEM

CPES Integrated 

EMI Filter

August 24, 2006 9

Issues for IPEM Building Block Approach

• Basic building blocks 

– “A minimum set of building blocks with 

integrated functionality, standardized interfaces, 

suitability for mass production, and application 

versatility.”

• Architecture & Partitioning

– How to build a power system application with 

application-independent PE modules? 

• Interface Characterization

– What are interface characteristics and 

requirements for a selected architecture?

85
August 24, 2006 10

Topologies Based on Totem-pole 

Phase-leg Modules 

Half-Bridge

Multi-Phase

Full-Bridge

Multi-Level

Single-Ended

Three-Phase

August 24, 2006 11

Integrated Phase-leg PEBB

+ “Plug & Play” Control Architecture

Serial Communications Link & Control Power Supply

Floating

Power

Supplies

Optical

Isolation

Gate

Drive Snubber

Optical

Isolation

Gate

Drive Snubber

PWM

Generator

Fault & Error

Logic

Communication

Control

Current & 

Temperature

Measurement

+

_

AC

T

A

V

125 Mb/s POF Daisy-Chained Serial Bus (PESNet)

Universal Controller

(Application Manager)

Smart Phase-Leg PEBBs (Hardware Managers)

...

35 kVA, 800 V, 20 kHz

86
August 24, 2006 12

Passives and Filters Need to be Integral 

Part of the Converter

T h e r m a l E n e r g y

Active

Passive IPEM

Filter IPEM Filter IPEM IPEM

Control Module

• Active IPEM 

Controls the energy flow (switching)

• Control Module

• Passive IPEM

Absorbs high-frequency energy (temporary storage)

Size reduces with increasing switching frequency

• Filter IPEM

Blocks high-frequency energy (size independent of switching frequency)

August 24, 2006 13

1 kVA, 1-AC (90-260 V) to DC (48 V) Isolated 

Converter

Discrete Components

Passive IPEM

Discrete EMI Filter

EMI Filter IPEM

Active IPEM

87
August 24, 2006 14

& Software

Architecture, Control HW/SW

- Hierarchical System Architecture

Control 

Network

Information System

Universal 

Controller 

+

–

+

–

+

–

+

–

PEBBs

Electric Power System

Power 

Converters

August 24, 2006 15

Specifications

• AC voltage: 208 V

• DC voltage: 400 V

• Power rating: 20 kW / unit

• Switching freq: 32 kHz

DC bus

PEBB unit

PEBB unit

Modular Converter Systems

iZ

• Example: Parallel Converters

5 A /d iv

I a 1

I a 2

5 A /div

I a 1

I a 2

AC

Currents

88
August 24, 2006 16

PEBB modules with standardized interfaces

Modeling and Characterization

- Standard cell interface characterization

Control Interface

Electro-Magnetic

Interface

Structural

Interface

Thermal Interface

Electrical

Reduced amount of

data

Hierarchical

knowledge PEBB

datasheet

Avoid poor power

capability usage

Cover wide spectrum

of applications

PEBB based power electronics design for non-experts

Thermal Control Mechanical Modeling

August 24, 2006 17

Modeling and Simulation

as Partition Evaluation Methodology

• Physics-based modeling

– Takes into account (within and without)

• Energy fields

• Materials

• Assembly

• Enables system-level evaluation

– Terminal models of subsystems

• Power: v, i

• Control: u

• Thermal: θ, p

• Structural (mechanical)

• Explicit relationships between terminal variables, while 

indirectly capturing internal physics

• Hierarchical reduction of modeling detail

Electrical Model

Thermal Model

Mechanical Model

Power Converter

89
August 24, 2006 18

PCS with Integrated Functionality 

• With active control and built-in intelligence, power 

converters can change the dynamics of the sources 

and loads to:

– Reduce system complexity by decoupling the dynamics 

(benefits in design & operation)

– Reduce the oversize margin for sources and loads

– Replace/eliminate bulky passive filters

• Functionalities:

– Power flow control

– Power management (continuous)

– PQ control, active filtering

– Monitoring, diagnosis, and on-line mitigation

– Protection

August 24, 2006 19

700

900

1100

0.000 0.050 0.100 0.150

Time [s]

0

100

200

300

Bus Voltage [V] Source Current [A]

With Intelligent Control

700

900

1100

0.000 0.050 0.100 0.150

Time [s]

0

100

200

300

Bus Voltage [V] Source Current [A]

330 A

30 A

Subsystem Interaction Example 

– models with input & output impedances –

+ Front-End MV Converter

Battery

960 V dc bus

vL1 with 2% short-circuit impedance vL2

Load 1

Converter

Load 2

Converter

iL1 iL2

Iomax

250 A

Const.

50 A

Iomax

250 A

30 to 330 A voref

1,000 μF

700

900

1100

0.000 0.050 0.100 0.150

Time [s]

0

100

200

300

Bus Voltage [V] Source Current [A]

With large bus capacitor

Power 

Management

and Control

90
August 24, 2006 20

• CPES promotes an integrated system approach via 

Integrated Power Electronics Modules (IPEM) 

concept to improve performance, reliability, and 

cost-effectiveness of power converters

• IPEM building blocks need passive and filter 

modules in addition to active modules

• Benefits can be achieved, and researches are 

needed at module, converter, and system levels 

• There is a strong need for consistent, physicsbased, system architecture analysis and evaluation 

methodology

Summary

August 24, 2006 21

Acknowledgement

The work and contributions are result of many CPES faculty, students, and staff.

This work was supported primarily by ERC Program of the National

Science Foundation under Award Number ECC-9731677 and by 

Office of Naval Research over the years

Many other US government and industrial sponsors of CPES research

are gratefully acknowledged.

91
CEC, 24th Aug 2006 GV -1

Bricks and Buses

Giri Venkataramanan

University of Wisconsin-Madison

Giri@engr.wisc.edu

Ph: 608-262-4479

24th Aug 2006

California Energy Commission

Sacramento, CA

CEC, 24th Aug 2006 GV -2

Power Electronics Applications

• Motor drives 1 h.p. – 5000 h.p.

• Power supplies 10W – 5 kW (and >)

• UPS systems 100W – 100kW

• Compact fluorescents 5W – 50W

• Segmented markets

• DG as a new market segment?

92
CEC, 24th Aug 2006 GV -3

Typical schematic

Vdc

SA1

SA2

SB1

SB2

SC1

SC2

I

dc

Lf Lf Lf ILfA I

LfB ILfC

VNf

VCfA VCfB VCfC

Cf Cf Cf

VAp VBp VCp

VcnL

VbnL

VanL

VnL

TAC TBA TCB Ta Tb Tc Za

Zb

Zc

I

Lda ILdb I

Ldc

I

tiea

Itieb

Itiec

Lt Lt Lt ILtC I

LtC ILtC

CEC, 24th Aug 2006 GV -4

State of the art

93
CEC, 24th Aug 2006 GV -5

Power Electronics Assembly

CEC, 24th Aug 2006 GV -6

Restraints

• Barriers to growth

– High cost

– Low reliability

– High complexity

– Custom design

– Long design cycle

– High manufacturing cost

– Low volume

– Custom interfaces

– Lack of scalability

– Multi-geometric assembly

94
CEC, 24th Aug 2006 GV -7

Desirable scenario

•Standardized input, output, functionality

•‘Compilable’ cabinets

•Fault tolerant, fail safe capability

•Plug and play

•Geometries for:

Thermal 

Electrical & Magnetic

Mechanical & Industrial design 

CEC, 24th Aug 2006 GV -8

MCCB Panel Boards (EATON)

95
CEC, 24th Aug 2006 GV -9

Modular servo drives (Rockwell)

CEC, 24th Aug 2006 GV -10

Components

Source Load

Electronic Power Converter

Power Converter Elements

Connective

Networks

 Electrical

 Thermal

 Control

Structural

96
CEC, 24th Aug 2006 GV -11

Silicon scaling

CEC, 24th Aug 2006 GV -12

Bricks & Buses Concept

Physical Realization

Aux Power Bus

Power

Sensor

Brick

Power

Control

Brick

Control Bus

Pole Bus

Throw Bus

Power Switching Brick

Sensor Bus

Auxliary

Power

Brick

97
CEC, 24th Aug 2006 GV -13

Bricks and Buses Converter

CEC, 24th Aug 2006 GV -14

Bricks and Buses Converter

98
CEC, 24th Aug 2006 GV -15

Bricks and Buses Converter

CEC, 24th Aug 2006 GV -16

Test results

88

89

90

91

92

93

94

0 20 40 60 80 100

IGBT Duty Ratio (%)

Net Efficiency (%)

Vdc = 250 V

Vdc = 400 V

99
CEC, 24th Aug 2006 GV -17

Radiated Coupling

Location

VPK-PK / Area 

(mV/cm2)

A 0.413

B 0.263

C 0.620

CEC, 24th Aug 2006 GV -18

Bricks & Buses

• Standardized dimensions – depth and 

height

• Incremental scaling of width

• Each brick thermally self managed 

• Variable volume

• Proportional scaling of surface area

• Decoupled power bus and signal bus 

• Contained interconnect EMI

100
CEC, 24th Aug 2006 GV -19

3 phase ac-dc-ac converter

Control Interface Unit Control Interface Unit Control Interface Unit

ACIN 1

ACIN 2

ACIN 3

ACO 1

ACO 2

ACO 3

CEC, 24th Aug 2006 GV -20

Accomplishments to date

• $70k demonstration seed through CERTS DG 

Integration (2001-2004)

• Demonstrated a concept prototype

• Adhoc design

• Comparable electrical performance

• Increased power density

• Modular packaging

• Improved manufacturability

101
CEC, 24th Aug 2006 GV -21

Challenges

• Electronics – Silicon

• Capacitors – Film, Foil

• Magnetic elements – Copper, Iron

• Cooling – Heat-sink, Cold plates

• Auxiliary – Switchgear

• Interconnections – Printed circuits, 

busbars

• Design, manufacturing, applications

CEC, 24th Aug 2006 GV -22

Magnetics - trends

Copper

Steel

102
CEC, 24th Aug 2006 GV -23

Beyond Si - Cellular design

• Cell definition

– Switch

– Throw capacitance

– Pole magnetics

– Thermal

CEC, 24th Aug 2006 GV -24

Step and repeat process

• Conforming and compatible layers 

– Thermal management

– Switching electronics

– Reactive elements

– Control/communication (soft)

103
CEC, 24th Aug 2006 GV -25

Air-cooled concept designs

CEC, 24th Aug 2006 GV -26

Liquid-cooled concept designs

104
CEC, 24th Aug 2006 GV -27

Bus Centered Assembly

• Electrical and structural interconnection

• Similar to MCCB panel-boards

CEC, 24th Aug 2006 GV -28

Roadmap

Control Interface Unit Control Interface Unit Control Interface Unit

ACIN 1

ACIN 2

ACIN 3

ACO 1

ACO 2

ACO 3

Cellular and

Distributed Control

Development

How to ensure that the

different cells perform the

control function as desired?

Geometric

Scaling

Studies

What should be the aspect ratio

of capacitors, magnetics and

thermal devices so that their

footprints can be compatible

with switching electronics?

Interconnect

Development

How to integrate the

thermal layer, switching

layer, and reactive

component layer together

structurally to allow

electrical and thermal flow,

in a inexpensive process?

Manufacturing &

Design Process

Development

105
1

Advanced Topologies

for DE Interface

Ned Mohan

University of Minnesota

Distributed Energy Workshop

Sacramento, CA 

August 24, 2006

2

Workshop on Renewable Energy for Minnesota

McNamara Alumni Center, University of Minnesota, Minneapolis 

Thursday October 12, 2006 

Objectives: 

• Discuss renewable energy prospects in Minnesota 

• Bring renewable energy curriculum into K-12 

• Describe the research being conducted in this field in the Department of Electrical and Computer

Engineering (funded by XcelEnergy, National Science Foundation and ONR) 

Who should Attend: Everyone concerned with energy, particularly the technical issues, and its impact on the

environment and society. 

Tentative Schedule: 

7:30-8:00 Registration, Coffee and Rolls

8:00-8:30 Welcome and Introduction

•Welcoming Remarks: Steven Crouch, Dean – Institute of Technology, U of M 

•Workshop Objectives and Agenda: Ned Mohan, ElectE, U of M 

•Renewable Energy Development Fund: Michelle Swanson, XcelEnergy 

8:30-10:00 Renewable Energy Overview

• A Power Grid for the Hydrogen Economy: Thomas Overbye, Professor, University of Illinois 

• Lessons From Norway: Terje Gjengedal, Vice President - STATKRAFT, NORWAY, in charge

of renewable energy projects 

• What is Happening in Minnesota?: Michael Bull, Assistant Commissioner, Minnesota

Department of Commerce (invited) 

10:00-10:30 Coffee Break

10:30-11:30 Wind Energy

• Present Projects and Potential in Minnesota: John Dunlop, American Wind Energy Association 

• Transmission Planning in Minnesota – CapX 2020: Gordon Pietsch, Great River Energy 

11:30-12:00 Research in Renewable Energy at the ECE Dept, University of Minnesota 

•Results of Research funded by NSF, XcelEnergy and ONR: Ned Mohan, ElectE, U of M 

12:00-1:00 Lunch (buffet lunch provided) 

1:00-2:00 Hydrogen and Fuel Cells: Making the Connection

•Hydrogen From Wind: Lanny Schmidt, Regents Professor, ChemE, U of M 

• Research in Fuel Cells: Brad Palmer, Cummins Power Generation, Fridley, Minnesota 

2:00-3:00 Bringing Renewable Energy and Conservation Curriculum into K-12 Courses

• Sustainable Architecture: Virajita Singh and John Carmody, U of M 

•Group Discussion led by: Steven Pullar, Woodbury Math and Science Academy, MN and

Michael Maas, Eden Prairie High School, MN 

Posters on Display: Research being conducted in this field in the Department of Electrical and Computer

Engineering, funded by XcelEnergy, National Science Foundation and ONR. 

106
3

4

Sources of Distributed 

Energy

 Photovoltaic

 Fuel Cells

 Wind

 Micro-Turbines

107
5

An Ultra-Compact High-Efficiency DC-DC SoftSwitching Converter for Photovoltaic and Fuel Cells

(US Patent:6,310,785 University of Minnesota )

+

−

Vin

+

−

Vo T1 T2

TA

+

+

−

vrect

iin

1 2 44 3 441 2 44 3 44 half - bridge portion phase modulated

full - bridge portion

−

TA

−

TB

+

TB

−

• Combination of uncontrolled

half-bridge and phase shifted

full-bridge

• Uses 4 switches with combined

VA ratings identical to PMC

9 ZVS down to no load

9 Reduced magnetics 

9 Smaller conduction loss

compared to PMC

9 Better dynamic response

6

Operating principles

+

−

Vin

+

−

Vo

T1 T2

− + vT1 + − +

−

vrect

iin

A B

+

−

v bridge

V

V

n D n o

in

= + 1

2 2

Vin

2

Vin

2 vT2

Lo TA

+

TA

−

TB

+

0

0

0

0

0

Vo

vA

vT1

vT2

vbridge

vrect

TB

−

TB

+

TB

−

TA

+ TA−

• all switches switch at 50% duty-ratio

and constant switching frequency

108
7

Experimental waveforms

vDS

vGS

−12V

vGS

vDS

Vo

vrect

vrect vrect

Vo Vo

+12V

−12V

−12V

vGS

350V

0

100ns

350 400

36 60

20

100

in

o

sw

V: V V

V: V V

@ A

f : kHz

−

−

8

L2

load I

D1

L1

D2

Vo

S1 S3 S5

S2 S4 S6

Vin

←

Io

1:n1

T1

1:n2 T2

*

* *

* 0

vsec*

*

HPMC with Current Doubler

109
9

A Multi-Port DC/DC Converter

Hariharan Krishnaswami, Ned Mohan, Department of Electrical & Computer Engineering, University of Minnesota

Objective:

The goal of this project is to develop a compact & efficient dc/dc converter that can serve as an interface between 2 or 

more energy sources (e.g., Fuel cells, PV array, batteries) and the load. Such a converter is termed a multi-port converter 

with each port connected to a source or a load.

Characteristics of the multi-port converter:

1. A single converter interfacing with several energy sources leads to part count reduction.

2. Power flow can be controlled from different energy sources to load.

3. Each port of the converter is bidirectional in nature, for example, a battery needs a bidirectional port.

4. Applications are in hybrid vehicles, pluggable hybrids and residential homes/buildings.

Proposed converter topology

The block diagram shows two 

sources Fuel cell and battery 

interfacing with a motor drive 

inverter. The battery and inverter 

ports are bi-directional.

10

Advantages of proposed converter topology:

1. The proposed converter circuit is the dual of the existing voltage fed multi-port converter

2. The source current ripple is reduced due to the inductor at the input.

3. High step-up of voltage possible due to the inverse topology.

4. Power flow control is by varying the phase shift between the full bridges as shown in the block diagram.

5. By appropriately selecting the turns ratio and matching the voltage levels of the sources and the load, Zero Current 

Switching (ZCS) can be achieved over a significant range of load and input voltage variations.

Principle of operation:

The equivalent circuit for analysis can be reduced to high frequency square wave current sources I1,I2 & I3 derived from 

the input dc currents IFC, IBatt and Iload respectively. The capacitors are reflected to the secondary of the transformers. The 

resultant power flow equations between ports 1(Fuel cell), 2(Battery) and 3(Load) are given in eqn.1. The final load voltage 

expression after some algebra is also given in eqn. 2. 

A Multi-Port DC/DC Converter

Hariharan Krishnaswami, Ned Mohan, Department of Electrical & Computer Engineering, University of Minnesota

'

1 13

123

'

2 12

123

'

3 23

123

111

111

111

C CC CCC

C CC CCC

C CC CCC

⎛ ⎞ = ++ ⎜ ⎟ ⎝ ⎠

⎛ ⎞ = ++ ⎜ ⎟ ⎝ ⎠

⎛ ⎞ = ++ ⎜ ⎟ ⎝ ⎠

13

13 13 '

1

21

21 21 '

2

32

32 32 '

3

1

2

1

2

1

2

FC O

s

Batt FC

s

Batt O

s

I I P C T

I I P C T

I I P C T

φ φ

φ φ

φ φ

⎛ ⎞ ⎜ ⎟ = − ⎜ ⎟ ⎜ ⎟ ⎝ ⎠

⎛ ⎞ ⎜ ⎟ = − ⎜ ⎟ ⎜ ⎟ ⎝ ⎠

⎛ ⎞ ⎜ ⎟ = − ⎜ ⎟ ⎜ ⎟ ⎝ ⎠

'

2 23 13

' ' 23 13

12 3 1

12

1 1 2 2 1 2

FC Batt

O

s s

s

C V V V C C T T

T

φ φ φ φ φ φ

⎡ ⎛⎞ ⎛⎞⎤ = −− − ⎢ ⎜⎟ ⎜⎟⎥ ⎛ ⎞ ⎢⎣ ⎝⎠ ⎝⎠⎥⎦ ⎜ ⎟ −

⎝ ⎠

(1)

(2)

110
11

MC1 MC2

Open-Ended MC Matrix Converter AC Motor ≡

MC1 MC2

Open-Ended MC Matrix Converter AC Motor ≡

SiC-Based

Matrix Converters for Open-Ended 

AC Drives for Wind Generators and 

Micro-Turbines

12

Press Release 2006

- 110 kVA SiC-based Inverter by Kansai 

Electric and CREE

- 50% less conversion losses compared 

to Si inverters

Advantages of SiC Devices

- Closer to an ideal switch

- Lower Losses; Higher Efficiency

- High Temperature; Compact Design

111
13

Power Electronic Systems

Figure 1-19 Load-side converter in a voltage-source structure. 

conv1 conv2

controller

utility Load

Figure 1-17 Current-link structure of power electronics interface. 

AC1 AC2

- Voltage-Link

- Current-Link

14

Problems with the Storage Capacitor:

1. Weight and cost

2. Reliability

3. Inrush Current at switch-on 

4. Additional currents under input unbalance

5. Difficult to integrate motor and the inverter

Figure 1-19 Load-side converter in a voltage-source structure. 

conv1 conv2

controller

utility Load

- Voltage-Link

112
15

Matrix Converters

• Direct-Link (no energy storage)

•Ideal with SiC Devices

AC Machine

AC Source

16

vC v vA B

vc

vb

va

ia

daA

dbA

dcA

daB daC

dbB dbC

dcB dcC

aA d

bA d

cA d

aB d

bB d

cB d

aC d

bC d

cC d

A

i Bi Ci a

i

b

i

c

i

av

bv

c v

Av Bv Cv

daA

daA + dbA

daA

daA + dbA

0 

daA + dbA+ dcA = 1

qaA

qbA

qcA

Highly Simplified Control of Matrix 

Converters

ONR Grant: N000140510291

113
17

Laboratory Demonstration

- Novel : Intellectual Property Disclosure

- Papers Attached

- IEEE-PESC 2006 and IEEE-APEC 2006

18

, ˆ V V d LL in =

Vd

+

−

+ − V V ph m ph in , , =

Vph in,

, ˆ V V ins LL in =

Conventional Voltage-Link System

Open-Ended Machine Supplied by Two Matrix Converters Vph in,

+ − , , 1.5 V V ph m ph in =

, ˆ , V V ins ph in = ˆ V V ins ph in =

MC1 MC2

Nearly Doubling (1.876) the Drive Output

114
19

Switching of Common Mode Voltages 

Results in Bearing Currents

- SiC devices will make this more acute

Source: Prof. Gopakumar, IISc

20

, , 1.867 V V ph m ph in =

Vph in,

V V ins ph in = ,

Vph in,

MC1 MC2

Y − Δ

34.5kV

Y Y−

Isolated Inputs with 30 deg phase shift

- Power Capability increases to 186.7%

- Ideal for Wind Electric Systems as shown below

115
21

1 T pu em =

, m 0 0.5pu 1.0pu 1.5pu ω f

1.5 V pu m =

1.0 V pu m =

proposed

proposed

conventional

conventional

Capability Curves with Common 

Mode Voltages Eliminated*

* Extended to 1.867 pu if input voltages at two sides are 

isolated from each other and 30 deg phase shifted

22

Simultaneous Benefits

1. Increases available voltage to 150%*

• rated torque up to 150%* of the rated speed

• 150%* power output capability

2. Bearing currents are eliminated

3. Slot insulation reduced by a factor 1.73

4. Comparable efficiency at the rated power?

5. Smaller current ripple?

6. Input power factor is controllable

7. Elimination of Energy Storage Capacitor

• Bulky, inrush current, current under unbalance

* 186.7% if isolated inputs and 30 phase shifted

116
23

Flywheel Battery  Objectives of Flywheel Battery

 Firm up wind resources on a short-term basis

 Interface with alternative generation

 Voltage support to the transmission grid

 Flywheel Battery Components

 Wheel – made with lightweight composites

 Enclosure – designed to maintain a low 

windage loss environment

 Magnetic Bearings – used for low rotational 

loss

 Motor/Generator – charges and discharges the 

battery

 Power Electronics and Controls – Control the 

Motor/Generator and Magnetic Bearings

 Flywheel Battery Specifications

 Power = 2 MW

 Energy = 100 kWhrs

 Speed range = 7,500 to 15,000 rpm

 High in-out efficiency

 Lowest cost possible

Stator dia. = 19 in

Length = 42 in

24

Synchronous Reluctance Motor/Generator

 Synchronous reluctance machine

 Low cost and no loss at idle

 Relatively low rotor loss

 High rotor operating temperature of 

250 °C (Most important)

 Large ratio of Ld to Lq inductance

 Axial Laminated small-scale rotor 

designed due to high Ld/Lq ratio

 Machines tested in back to back setup

 Machine able to operate at high speed

 Due to thickness hot rolled steel used 

for magnetic layers

Ld

Lq

117
25

Control of a Doubly-Fed Induction Wind Generator 

Under Unbalanced Grid Voltage Conditions

stator

rotor

grid

AC

DC

DC

AC

DFIG

DC link

26

Application of Series 

Compensation in Wind Power

118
27

Innovative Methods to Triple Efficiencies of FAN Motors

( )a ( )b Low 25.97 11%

Mid 34.12 18%

Fan 3 High 51.86 29%

Low 35.82 21%

Mid 43.17 26%

Fan 2 High 56.2 31%

Low 67.69 14%

Mid 91.4 26%

Fan 1 High 118.81 28%

Speed Setting Input Power (W) Efficiency

• Max Efficiency = 30%

• Starting Problem

• Poor Power Factor

• Pulsating Torque

• Low efficient speed 

regulator

• Efficiency goes further 

down at low speed

• High Efficiency (close to 90%)

• Power factor close to 0.9 (Design dependent)

• Can be wound with the available winding technology 

for AC machine

• Easy to manufacture, small size, ease in winding 

(Outer rotor)

• Low cost, readily available ferrite magnet as 

permanent magnet

• Low assembly cost and not a multi-step process

Present FAN motor

Proposed FAN motor

28

0.966 1000 50 108.7 101 7.68 123.2 0.88 0.93 165 1 0

(N-M) (Rpm) (Hz) (W) (W) (W) (VA) (PU) (PU) (V) (PU) (deg)

Torq RPM Freq P_in P_out P_loss VA P.F. Effic CktVs PwmIndx AF_ang

SIMULATION RESULT : Outer Rotor Configuration

119
29

FEM

RESULTS

Iron Loss density COST ANALYSIS Flux density 

A compromise in efficiency (by 5- 8%) can reduce the total cost of motor by 20-30%, Present 

target is to achieve the highest efficiency possible at low cost

** For a fair comparison, analysis is done at almost equal losses

Ferrite 66.6 2.71 3.34 4.4 122 4.03 3.65 7.68 10.45

Hybrid (60% Neo,40% Ferrite) 24.63 7.17 3.102 2.99 110 4.86 3.8 8.66 13.26

Neo (NdFeB) 22.12 11.06 2.79 2.39 100 4.36 4.22 8.58 16.24

Total Cost 

($)

Total 

(Loss, 

W)

Iron 

Loss 

(W)

Cu Loss 

(W)

Size of 

machin

e (mm)

Cu Cost 

($)

Cost of 

Steel ($)

Cost of 

PM ($)

Volume 

required 

(PM in cm3)

Material

120
11/2/2006 1

Integrated Modules

Simplify Systems Design

By: John Mookken

SEMIKRON USA

8/24/06

Advanced Power Electronics DE Workshop

Sacramento, CA

11/2/2006 2

Evolution of the Power Module

121
11/2/2006 3

Why Integrate?

Shorter time to market

Easier system design & assembly

Economical

Reduced number of components

Customized solution without the custom pricing

Standard Interface

Commonality or standard platform

11/2/2006 4

SKAI: Block diagram

I

I

V

T

Heat Sink

Power Supply Gate Driver Protection

Controller CAN 

communications

temperature

voltage

current

122
11/2/2006 5

SEMIKUBE

« A 390A rectifier + inverter

into a 400mm cube »(*)

Includes all sensing (current, 

voltage, temperature)

(*) actual max dimensions are 412 x 435 x 380

11/2/2006 6

SKAI: Components

Cover

Driver / Controller board

Sealed 14 pin connector

Current sensors

DC Filter Capacitor

DCB /w Si devices

Heat sink

Power terminals

1200/600V IGBT SKAI module

123
11/2/2006 7

Load

Intelligent 

Power 

Module

(AFE)

Intelligent 

Power 

Module

(Inverter)

Communications

Coolant 

In Coolant 

Out

Aux. power

Line current

& Voltage

Load

feedback

EMI Filter

AFE / Inverter Example

11/2/2006 8

DC/DC Example

Load

Intelligent 

Power 

Module

(Inverter)

Communications

Coolant 

In Coolant 

Out

Aux. power

Load

feedback

Intelligent 

Power 

Module

(H-bridge)

124
11/2/2006 9

Example Systems

11/2/2006 10

Load

Intelligent 

Power 

Module

(H-bridge half)

Communications

Coolant 

In

Coolant 

Out

Aux. power

Intelligent 

Power 

Module

(H-bridge half)

H-Bridge Example

Dual modules assembled

on motor end bell / heat sink 

125
11/2/2006 11

SKAI: Heatsink Options

Metal Plate

Liquid

Air

Options available with

LV or HV SKAI modules

Modules can also be assembled 

on custom heat sinks on request

11/2/2006 12

IPM: Solution

SKAI core

Customer adds

Application Specific Application software

SKAI module

Heat sink

Driver/Controller 

Current Sensors

Choose Std. SKAI options

126
11/2/2006 13

www.SEMIKRON.com

Thank you

for your attention

John Mookken

John.mookken@semikron.com

Questions or

Comments ?

127
Distributed Energy

Advanced Power 

Electronic Interfaces

Ben Kroposki

National Renewable Energy Laboratory

Distributed Energy (DE) Applications

Photovoltaics

Fuel Cells Microturbines

Reciprocating Engines

Advanced Turbines Wind

• Energy Management

• Electricity to Grid

• Baseload/CHP

• Peak/Demand Reduction

• Reliability/Backup Power

• Power Quality

• Grid Ancillary Services

128
Distributed Energy 

Resources

Interconnection 

Technologies

Electric Power 

Systems

Fuel Cell PV

Microturbine Wind

Utility Grid Simulator

Generator

Inverter 

Switchgear, 

Relays, & Controls

Functions

•Power Conversion

•Power Conditioning 

(PQ)

•Protection

•DE and Load Control

•Ancillary Services

•Communications

•Metering

Micro Grids

Energy 

Storage

Loads

Local Loads

Load Simulators

Utility 

Grid

DE Grid Interconnection

Interconnection System

(within dot-dash lines)

Transfer 

Switch or 

Paralleling

Switchgear

Local EPS 

Protective

Relaying

Power 

Conversion

DER 

Electric

Generator

DER 

(prime 

movers,

energy 

storage))

Power 

Distribution

AC Loads DC Loads

Area EPS

Protective

Relaying

Area EPS

Power 

System

(grid)

DER 

control

DER 

monitoring/

metering

Dispatch 

and control

Point of Common 

Coupling

Meter

Power Flow

Communications

The interconnection system (within the dotted line) is designed to handle the power between 

and serve as the communication and control gateway among the DER, the Area EPS and the 

customer loads. Workshops with industry provided a forum for furthering this activity and 

several manufacturers are working on developing and validating standardized, advanced, 

universal interconnection technologies [NREL/SR-560-32459].

Interconnection System Functional Block Diagram

129
PE Applications with DE Systems

PE PE

PE

DE Power Electronic 

Interfaces

Benefits of Power Electronic 

Interfaces for DE

• Improved Operating Efficiencies

– Variety of topologies for power electronic 

interfaces can improve conversion 

efficiencies

– Allow for variable speed operation of 

internal combustion engine DG

130
Benefits of Power Electronic 

Interfaces for DE

• Power Quality

– Harmonic Control

– Power for Sensitive Loads

0

20

40

60

80

100

120

140

0.01 0.1 1 10 100

Time (s)

Percent of rated voltage (%)

IEEE 1547 (2003) Trip Limits

ITI (CBEMA) Curve (2000)

Areas of Interest

(1)

(2)

(3)

0.16 2 0.5

• Sustained Interruptions –

DE can provide backup power 

if designed to do so. This may 

improve reliability if designed 

and operated properly.

• Voltage Regulation – DE can 

provide voltage regulation if 

allowed. This can also be a 

limiting factor as to penetration 

on a feeder.

• Harmonics – There are 

harmonic concerns with both 

rotating and inverter based 

DE. 

• Voltage Sag – DE may be 

able to help keep voltage up, 

but only if allowed to do so.

Benefits of Power Electronic 

Interfaces for DE

• VAR Support and Voltage Regulation 

θ1 = 36.8°

+jQ 

(lag)

PLoad

θ2 = 52.7°

-PDE

Real Power (W)

S1

S2

QLoad

DG

Range A

w/o DG

with DG

Power Factor 

Voltage Regulation 

131
Benefits of Power Electronic 

Interfaces for DE

• Reduced DE Fault Currents

– Ability to recognize dI/dt of fault currents and 

clamp or disconnect

– This allows for use of DE on networked systems 

and easier integration with protection system

• Interoperability with a variety of other DE 

sources

• Standardization and Modularity

– High volume manufacturing techniques

1547-2003 Standard for Interconnecting Distributed Resources 

with Electric Power Systems

1547.1-2005 Conformance Test Procedures for 

Equipment Interconnecting DR with EPS

P1547.2 Application Guide for IEEE 1547 

Standard for Interconnecting DR with EPS

P1547.3 Guide for Monitoring, Information 

Exchange and Control of DR

Guide for Grid/DG 

Impacts Determination

DG Specifications 

and Performance 

Interconnection 

System Certification Guide 

Current Projects Future Projects

P1547.4 Guide for Design, Operation, and 

Integration of DR Island Systems with EPS

P1547.6 Recommended Practice for 

Interconnecting DR With EPS Distribution 

Secondary Networks

P1547.5 Guidelines for Interconnection of 

Electric Power Sources Greater Than 10 MVA 

to the Power Transmission Grid Covers IEEE 1547 

Section 4.3.2

Covers IEEE 1547 

Section 4.1.4

IEEE 1547 Series Standards

Power Electronic Interface 

Specifications for DR

132
IEEE 1547.1 Interconnection Tests have been incorporated 

into UL 1741 for product certification

UL 1741

Interconnection 

Equipment

•Construction

•Protection against risks 

of injury to persons

•Rating, Marking

•Specific DR Tests for 

various technologies

IEEE 1547

Interconnection 

System Requirements

•Voltage Regulation

•Grounding

•Disconnects

•Monitoring

•Islanding

DE Interconnection Equipment Certification Approach

IEEE 1547.1

•Interconnection 

System Testing

•O/U Voltage 

•and Frequency

•Synchronization

•EMI

•Surge Withstand

•DC injection

•Harmonics

•Islanding

•Reconnection

Grid 

Simulator

Load Simulators

Synchronous Generators

PV Array

3 AC Buses

Utility 

Grid

Battery 

Banks

3 DC 

Buses

Inverters

Fuel 

Cells

Electrolyzer

Microturbines

Wind Turbines

NREL DER Test Facility 

• Test 

Systems up to 

200kW

• Natural Gas 

on site

• All DER 

Technologies

• Full IEEE 

1547.1 testing

133
1 © 2006 Eaton Corporation. All rights reserved.

Modular and Scalable Power 

Converters in the UPS Industry

Ian Wallace

Eaton Corporation, Innovation Center

2 © 2006 Eaton Corporation. All rights reserved.

Content

 Eaton Overview

 Eaton Electric – UPS Business

 Today’s Critical Power Systems

 UPS Market Drivers

 Modern UPS converter technology

• Design for reliability 

• Scalability & Redundant Systems for high 9’s reliability 

• Topology and control 

 Modularity : Power Control

• Two examples:

• 9390 UPS power / control structure

• Blade UPS modularity / power density. 

134
3 © 2006 Eaton Corporation. All rights reserved.

•A global diversified industrial manufacturer 

 2005 sales: $11.1 billion

•A leader in:

 Electrical power quality and control

 Fluid power systems

 Automotive engine air management 

 Intelligent drivetrain and safety systems for trucks & heavy vehicles

Eaton Overview

Electrical Fluid Power Automotive Truck

4 © 2006 Eaton Corporation. All rights reserved.

What Markets Does Eaton Serve?

Industrial Facilities 

& Utilities

Residential

Telecom / Data Centers Commercial/Institutional Facility

135
5 © 2006 Eaton Corporation. All rights reserved.

Eaton Business Segment – Electrical

$3.7 billion sales in 2005.

14,000 employees, 57 factories in 19 countries

Æ electrical control, power distribution, UPS, 

industrial automation products & services, ...

• Power Quality Systems

• Power Component & Systems

• Electrical Components / Industrial Control

C-H Acquired

By Eaton

1979

Acquired

Powerware

2004

Acquired the

Electrical Group

Of Delta, plc

2003

Acquired DCBU

Westinghouse

1994

Founded in

Milwaukee

1893

6 © 2006 Eaton Corporation. All rights reserved.

Eaton Electrical – Power Quality Systems

• Mission Critical UPS systems for highest 

power reliability (emergency back-up)

• Single phase & three phase UPS

Modular, transformerless up to 160 kVA 

• Industrial & Rack-mount UPS

• Sag Ride-through Power Conditioner

• Active and Passive Harmonic Filters

• Static Transfer Switches

• Advanced Battery Management

• Integration & Global Service Support

30kVA

UPS 

160kVA

UPS

6kVA UPS 

Rack-mount

750kVA UPS

136
7 © 2006 Eaton Corporation. All rights reserved.

UPS Systems – Key to 24/7 Daily Life

3-phase UPS 3-phase UPS

Clean 

AC 

Power

Clean 

AC 

Power

¡ Data Centers

¡ Diagnostic Imaging

¡ Broadcast Transmitters

¡ Government Facilities

¡ Industrial Applications

¡ Servers

¡ Networks

¡ Computer Rooms

¡ Clinical lab equip.

¡ Bank ATM

¡ Industrial PLC

¡ Telecom

¡ Wireless

¡ DSL

¡ Central Office

¡ Customer Premise

1-phase UPS 1-phase UPS

Power Quality Power Quality

8 © 2006 Eaton Corporation. All rights reserved.

• Eaton is an industry leader and globally recognized 

provider of innovative, effective power quality solutions, 

delivered under the Powerware brand

 Power protection revenue ~ $900M

 #1 in worldwide UPS sales above 5 kVA

 #2 in worldwide UPS sales at and under 5 kVA

 Total volume: >1.5 million units / year 

 3-Phase volume: ~ 7,000 3-phase units / year 

 Large installed base of more than 45,000 3-phase UPSs 

worldwide

Eaton UPS Market Position

137
9 © 2006 Eaton Corporation. All rights reserved.

Eaton UPS Market Position 1 - 10kVA UPS10 – 60kVA UPS60 - 200 kVA UPS> 200 kVA UPS

% Revenue v.s. KVA

5,000 units

4,500 units 

2,500 units 

< 1kVA 

 1-5kVA

 5-20kVA

 20-50kVA

 50-200kVA 

> 200kVA

1.5M units

Servers

POS

General 

use

Small Data 

Centers

Light 

Industrial

Mid Size 

Data 

Centers

Industrial

Large Data 

Centers

10 © 2006 Eaton Corporation. All rights reserved.

122 active patents and 98 applications pending

1960 1970 1980 1990 2000

1962: First AC 

Power Inverter

1962: First AC 

Power Inverter

1968: First 

commercial 

UPS combining 

battery chargers 

and inverters

1968: First 

commercial 

UPS combining 

battery chargers 

and inverters

1972: First 

fault tolerant 

and parallel 

UPS

1972: First 

fault tolerant 

and parallel 

UPS

1982: First 

UPS suitable 

for computer 

rooms 

First UPS 

specifically 

designed for 

office

1982: First 

UPS suitable 

for computer 

rooms 

First UPS 

specifically 

designed for 

office

1986: First UPS 

over 100kVA for 

computer room

1986: First UPS 

over 100kVA for 

computer room

1987: First UPS 

with advanced 

PWM and 

microprocessor 

based 

diagnostics

1987: First UPS 

with advanced 

PWM and 

microprocessor 

based 

diagnostics

1989: First high 

frequency 

transformer-less 

UPS

1989: First high 

frequency 

transformer-less 

UPS

1996: First UPS 

with wireless 

paralleling

1996: First UPS 

with wireless 

paralleling

1993: Advanced 

Battery Management 

to extend battery life

1993: Advanced 

Battery Management 

to extend battery life

1993: First 

UPS to offer 

load segment

1993: First 

UPS to offer 

load segment

2004: Modular 

transformerless 

UPS up to 

160 kVA

2004: Modular 

transformerless 

UPS up to 

160 kVA

2001: 3kVA 

rackmount UPS 

increases power 

density by 40%

2001: 3kVA 

rackmount UPS 

increases power 

density by 40%

1976: First 

UPS for 

emergency 

lighting HID 

lamps

1976: First 

UPS for 

emergency 

lighting HID 

lamps

2003: 2nd generation 

wireless paralleling 

2003: 2nd generation 

wireless paralleling 

2002: First 

Monitoring in 

excess of 225,000 

data points

2002: First 

Monitoring in 

excess of 225,000 

data points

Eaton UPS Technology Leadership

2003: 6 kVA in 3U 

for high-density 

rack applications

2003: 6 kVA in 3U 

for high-density 

rack applications

2002: First dual 

source UPS for 

rack mount

2002: First dual 

source UPS for 

rack mount

138
11 © 2006 Eaton Corporation. All rights reserved.

• Main elements of Critical Power systems

Measured by 9’s of availability

 Multi-source / storage systems

• Utility (single / multiple feeds)

• DC Batteries

• AC Generator

• DC Flywheels & ultra capacitors

 UPS – one element in high 9’s system

• System design for redundancy

• UPS paralleling for redundancy and capacity

• Static UPS bypass

• Manual / Maintenance bypass

Today’s Critical Power Systems

12 © 2006 Eaton Corporation. All rights reserved.

Today’s UPS Market Drivers

Power quality under utility 

disturbances

Flexible architectures for high 9’s 

reliability

• Parallel redundancy

• Expandable for capacity

High system reliability, MTBF

• No single point failure

139
13 © 2006 Eaton Corporation. All rights reserved.

Today’s UPS Market Drivers

Low installation cost

Low operating cost - high efficiency

High power quality utility interface 

High power density 

Serviceability – MTTR

Multi - power source compatibility

Global sourcing and manufacturing

Monitoring, diagnostics & 

prognostics

Maintenance services

 Revenue Æ ~10% growth / yr

 Price Æ ~ 4% $ reduction / yr

14 © 2006 Eaton Corporation. All rights reserved.

Today’s UPS Technology 

Market drivers are addressed by:

• Design for reliability 

• Scalable multi-unit operation for high 9’s architectures

−Elimination of single point failures

−Fault identification and selective trip

• Power module topology and design

• Converter modulation and control techniques

• Modular power and control modules

−Build a scalable product line via modularity

140
15 © 2006 Eaton Corporation. All rights reserved.

Converter Design for Reliability

HALT: Highly Acceleration Life Test 

• Thermal cycling, rapid thermal transitions, load 

cycling ...

• Identify weakest link via product destruction

HASS: Highly Accelerated Stress Screen

• Ongoing production screening. 

• Verify production units continue meet reliability 

objectives

MTBF targets 

• UPS Converter > 60,000 hrs

• Parallel redundant systems > 300,000hrs

16 © 2006 Eaton Corporation. All rights reserved.

System Level Modularity and Scalability 

System Level Drivers:

Key to achieving high 9’s of reliability 

• parallel for redundancy

Parallel for capacity - load expansion

Enablers

• Eliminate single point failure

• power & controls

• Communication less paralleling

Hot SyncTM Technology

• Fault location detection

141
17 © 2006 Eaton Corporation. All rights reserved.

Power Availability for Mission Critical Apps

The power grid typically provides 3 - 9’s, or 99.9% reliability. 

This equates to almost 9 hours of downtime per year. ‘High 

9’s’ are generally considered to mean 6 - 9’s and above. 

9’s Downtime per Year

3 99.9% 8 hr, 45 min, 36 sec

4 99.99% 52 min, 33.6 sec

5 99.999% 5 min, 15.36 sec

6 99.9999% 31.5 sec

7 99.99999% 3.15 sec

18 © 2006 Eaton Corporation. All rights reserved.

Increasing Availability of Power

• Can provide “high 9’s” availability

 The best opportunity to increase availability at the source

• There are two fundamental technical issues to solve 

for parallel redundant power systems

 Control and stability of two or more AC power sources being 

paralleled

 Elimination of all potential system-level single-point-of-failure

• The resulting performance is depending on design 

implementation of:

 Load sharing

 Fault isolation

Parallel redundant systems offer 

substantially increased availability

142
19 © 2006 Eaton Corporation. All rights reserved.

Legacy Systems

• Single point of failure

• Fault propagation

• Noise sensitive

• Unreliable cables and 

connections

UPS

Module

#1

UPS

Module

#2

UPS

Module

#3

Load share and synchronization wiring between modules

Synchronization 

bus

Load-share 

bus

Limited to 

5x9’s

20 © 2006 Eaton Corporation. All rights reserved.

Legacy Systems

• Drastically increased system 

complexity

• Noise sensitive

• Who is right / who is wrong?

• Unreliable cables and 

connections

UPS

Module

#1

UPS

Module

#2

UPS

Module

#3

Master / redundant controllers

Ist Controller

2nd Controller

Limited to 

6x9’s

143
21 © 2006 Eaton Corporation. All rights reserved.

Powerware Hot Sync Hot SyncTM 

• Reduced system complexity

• No single point of failure

• Modules are identical

• Modules act as peers

• No Primary / Secondary 

relationship

• No “Main Intelligence Module”

required

UPS

Module

#1

UPS

Module

#2

UPS

Module

#3

“Wireless” paralleling of AC sources Can provide 

7x9’s

22 © 2006 Eaton Corporation. All rights reserved.

• No control wiring required between modules for current 

sharing or selective tripping

• Designed to share load with any power source, 

including the utility

• Provides flexibility and scalability

• The UPS can be decentralized into the server 

equipment and still operate in parallel with additional 

server racks

• Ideal for distributed power system applications

Powerware Hot Sync Hot SyncTM 

Hot SyncTM provides automatic load sharing and 

selective tripping in a parallel system.

144
23 © 2006 Eaton Corporation. All rights reserved.

Parallel load share control algorithm constantly 

drives the module to carry the least amount of load. 

This will drive Module 1 back in Phase with Module 2. 

Hot SyncTM Load Share Pictorial Module Load Level 

Module 2 Phase

Module 1 Phase

Module 2 Min Load 

Module 1 Actual Load Module 2 

In Phase 

Module 1 

Leading

Phase

•Eaton developed technology – US patents #5,745,356 & 

5,745,355

24 © 2006 Eaton Corporation. All rights reserved.

Hot Sync Hot SyncTM Benefits Benefits

• Can provide up to 7x9’s availability 

of power

• Ultimate scalability with no 

additional controls

• Modules in Parallel:

 are absolute peers

 have absolute autonomy

 use 100% intrinsic components

• Seamless transition from capacity 

to redundancy

• Increased serviceability 

Mains Bypass

Load

Direct extension to autonomous operation of grid interface 

Scalable DG converters

145
25 © 2006 Eaton Corporation. All rights reserved.

Input Power Quality and Efficiency

• Online UPS: maximum protection from utility disturbances 

• Source 3-wire and 4-wire loads. 

• Maintain efficiency > 95%

• Manage battery lifetime

Low power density

 Input line filters

 Output transformers

Previous Technology

AC Source 1 =

~

1 Phase

&

3 Phase

Bypass AC Source 2

Loads

Limited battery management

26 © 2006 Eaton Corporation. All rights reserved.

Input Power Quality & Efficiency

• Active front end IGBT Converters (10-200kVA) improve:

 Power quality, grid and generator interface

• Transformerless Double-Conversion UPS Topology

 Elimination of distribution transformers (4 wire source / loads)

 Novel modulation scheme for 4 leg inverters 

 Maximized DC bus utilization to maintain efficiency

 Ultra small filter size: optimization of 

magnetic component & switching frequency

Increased power density

146
27 © 2006 Eaton Corporation. All rights reserved.

•Battery Systems 

Advanced Battery Management:

• 3 stage charging technique - doubles battery life

& optimizes battery recharge time.

• Prognostics / Diagnostics- provides up to 60-day 

advanced notification of the end of useful battery life.

• ProActive Service – max uptime via 24x7 corrective 

maintenance, remote monitoring 

Battery Management

Source 1 = ~ =

~

1 Phase

&

3 Phase

Bypass

=

=

Source 2

Loads

28 © 2006 Eaton Corporation. All rights reserved.

Modular Product Approaches

• Motivation 

 Build a product line to cover wide power range

 Maintain low cost and high reliability

 Enable N+1 redundancy: high MTBF

 Serviceability - Maintain low MTTR

• Where is the appropriate division and extent of 

modularity ?

147
29 © 2006 Eaton Corporation. All rights reserved.

Modular Power Block Approach 

= ~ =

~

1 Phase

&

3 Phase

Loads

=

~ =

~

Embedded Controller

Power Module

=

~ =

~

30 © 2006 Eaton Corporation. All rights reserved.

Rack Mount Modular UPS 

• BladeUPS:

 12-60 kW modular, rack-based N+1 power protection 

• Features:

 Very compact design, high power density (6U).. 

 Highest power density on the market 

 No single points of failure in system

 Mounts in any industry standard rack

 Each module is autonomous - establishes peer-to-peer 

relationship when paralleled.

 Hot Sync reliability, redundancy, and scalability

• Scalable from 12kW to 60kW

 High Efficiency up to 97%

 Features hot-swappable battery modules and electronics

 Advanced Battery Management (ABM)

148
31 © 2006 Eaton Corporation. All rights reserved.

Thank You

149
California Energy Commission California Energy Commission 

Presentation for:

2

Presenter Presenter Presenter

Distributed Energy Applications Distributed Energy Applications 

Leverage High Volume, Leverage High Volume,

Modular Power Converters Modular Power Converters 

Advanced Power Electronic Interfaces

for DE Workshop

Sacramento, CA

August 24, 2006

Perry Schugart

Director, Power Converter Products

12 years, Power Semiconductors

9 years, Power Electronic Systems

Bachelor of Science, Physics

pschugart@amsuper.com

Phone: +1.262.901.6036

Fax: +1.262.901.0104

150
3

Modular & Configurable High Power Converters Modular & Configurable High Power Converters Modular & Configurable High Power Converters

• Programmable Electronic Building Blocks (PEBB)

• Configurable for different power conversion needs

• High volume, modular architecture

• Rapid product development 

4

Integrated Modularity with Power Pole Architecture

Heat sink – Liquid Cooled

+ Bus

- Bus

Output

System Fiber Optic I/O

Hardware

Interface

Pre-charge

Control

Interface

Heat sink – Air Cooled

or

Fan

IGBT

Main Filter

Current

Sensor

Voltage

Sense

Power Pole

Converter Control & Communication Power

Supply

Gate Driver

Thermal

Sensor

151
5

• Analog and digital I/O

• Dual digital signal processors

• Fiber optic communications

- CAN, asynchronous serial

PM1000 – Configurable Power Converter – Configurable Power Converter Configurable Power Converter

• Gate drivers

• Auxiliary power supply

• Cooling

- Liquid & air

Pre-charge

Control

Interface

Application

Module Control

Strategy

DSP1

Power Processor

Gate Driver

DSP2

Fiber Optic I/O

Power Pole 1 Power Pole 2 Power Pole 3

I/O & Communication 

Interface 

Embedded

Controller

& Control Interface

Power

Supply

Power Pole 8

System

Hardware

Interface Active Rectifier

DC-DC

AC Voltage Source

Motor Control

PM1000

PowerModule Power Converter

6

Rapid Product Development Rapid Product Development Rapid Product Development

From Concept 

to Converter

PM1000

Rapid Product Development

Makes it happen the quickest

152
7

Gained Advantage ($)

PM1000 Rapid Product Development Benefits PM1000 Rapid Product Development Benefits PM1000 Rapid Product Development Benefits

Production

System Integration

Iteration

S/W Development

H/W Development

S/W Design

H/W Design

System Design

PM1000

Typical OEM

In-house

Development

.25 m

1 m

.25 m

.25 m

0

0

0

1 m

1 m

1 m

2 m

3 m

2 m

2.5 m

1.5 m

1.5 m

∆ = 11.75 m

t = 0 14 2 4 6 8 10 12

Months

15 Product Dev. Time 14.5 m 2.75 m

8

Simplify Power Electronic System Development Simplify Power Electronic System Development Simplify Power Electronic System Development

CAN

Hub

Fiber Optic I/O

PM1000

CAN

Bridge 

n = 1

n = 2

n = 30

Ethernet 

Connector

Active Rectifier

DC-DC

AC Voltage Source

Motor Control

CSPS (IP) Active Rectifier

DC-DC

AC Voltage Source

Motor Control

CSPS (IP)

Active Rectifier

DC-DC

AC Voltage Source

Motor Control

CSPS (IP)

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

PDK SDK

PowerModule 

Asynchronous 

Serial Terminal 

Adapter 

Serial Port 

Connector

Fiber Optic I/O

PM1000 Active Rectifier

DC-DC

AC Voltage Source

Motor Control

153
9

PM1000 Product Developer Kit PM1000 Product Developer Kit PM1000 Product Developer Kit – PDK

PowerModule 

Asynchronous 

Serial Terminal 

Adapter 

Serial Port 

Connector

Fiber Optic I/O

PM1000 Active Rectifier

DC-DC

AC Voltage Source

Motor Control

10

PM1000 PDK

154
11

PM1000 PDK PM1000 PDK PM1000 PDK – Active Rectifier – Active Rectifier Active Rectifier

RX1TX1

RX2

PowerModule TM

TX2

RX3

TX3

RX4

TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 345 6789 2

PM1000

175

PM1000

175

Universal, High Power 

Converter - PM1000 

PowerModule

Asynchronous

Serial Terminal

Adapter

Controller / PC

Precharge

Contactor

C Cdamp

Ldamp

Rdamp

L

Phase C

Phase B

Phase A

AC Filter

Phase C

Phase B

Phase A

Phase B

Phase C

Phase A

+

-

DC

AC Load

Source

3-Phase

AC

Protection

Coil

Aux Cont

PS AC

or

DC

12

DC

+

-

+

-

DC

Source

PM1000 PDK PM1000 PDK PM1000 PDK – DC/DC Boost – DC/DC Boost DC/DC Boost

RX1TX1

RX2

PowerModule TM

TX2

RX3

TX3

RX4

TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 345 6789 2

PM1000

175

PM1000

175

Universal, High Power 

Converter - PM1000 

PowerModule

Asynchronous

Serial Terminal

Adapter

Controller / PC

C

L

Coil

Aux Cont

Precharge

Contactor

DC +

DC -

PS AC

or

DC

+

-

DC

Load

155
13

PM1000 PDK PM1000 PDK PM1000 PDK – DC/DC Buck – DC/DC Buck DC/DC Buck

RX1TX1

RX2

PowerModule TM

TX2

RX3

TX3

RX4

TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 345 6789 2

PM1000

175

PM1000

175

Universal, High Power 

Converter - PM1000 

PowerModule

Asynchronous

Serial Terminal

Adapter

Controller / PC

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection

DC

+

-

+

-

DC

Source

+

-

DC

Load

14

C Cdamp

Ldamp

Rdamp

Phase C

Phase B

Phase A

PM1000 PDK PM1000 PDK PM1000 PDK – AC Voltage Source – AC Voltage SourceRX1 TX1

RX2

PowerModule TM

TX2

RX3

TX3

RX4

TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 345 6789 2

PM1000

175

PM1000

175

Universal, High Power 

Converter - PM1000 

PowerModule

Asynchronous

Serial Terminal

Adapter

Controller / PC

Phase C

Phase B

Phase A

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection

DC

+

-

+

-

DC

Source

L

3-Phase

AC Load

156
15

PM1000 PDK PM1000 PDK PM1000 PDK – Motor Control – Motor Control Motor Control

RX1TX1

RX2

PowerModule TM

TX2

RX3

TX3

RX4

TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 345 6789 2

PM1000

175

PM1000

175

Universal, High Power 

Converter - PM1000 

PowerModule

Asynchronous

Serial Terminal

Adapter

Controller / PC

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection

DC

+

-

+

-

DC

3-Phase Source

AC Motor

16

PM1000 PDK Success Story PM1000 PDK Success Story PM1000 PDK Success Story – Stationary Fuel Cell – Stationary Fuel Cell Stationary Fuel Cell

P1

P2

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

J2

DC+ DCJ7 J6 J5 J4 J3VC1 VB1 VA1 BAT+ BATSHI Board

U1 D4 U3 D11

P3 -

+

DC

VC VB VA

P1

P2

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

PowerModuleTM

PM1000

175

J2

DC+ DCJ7 J6 J5 J4 J3VC1 VB1 VA1 BAT+ BATSHI Board

U1 D4 U3 D11

P3 -

+

DC

VC VB VA

DC

Protection

300

μF

200 μH

140A

x 3

Fuel Cell

(DC Source)

DC

+

-

DC - DC +

150

μH

 75

μH

Ldamp

Rdamp

125 μH

210A

x 3

AC

3-Phase

AC

Protection

Phase C

Phase B

Phase A

Phase B

Phase C

Phase C

Phase B

Phase A

Phase A

Aux Cont

Coil

Contactor

 Coil

 Coil

 Com

 Com

 PS

 PRCH

 Coil

 Coil

 Com

 Com

 PS

 PRCH

750VDC

480VAC

690VAC

60 Hz

50 Hz

DC/DC

DC/AC

2 PM1000 PDK’s

<1 week to demonstrate

Anode

Electrolyte

Cathode

157
17

PM1000 PDK Success Story PM1000 PDK Success Story PM1000 PDK Success Story – Fuel Cell Bus – Fuel Cell Bus Fuel Cell Bus 

3 PM1000 PDK’s

DC/DC boost converters

18

PM1000 PDK Success Story PM1000 PDK Success Story PM1000 PDK Success Story – Fuel Cell Bus – Fuel Cell Bus Fuel Cell Bus RX1 TX1 RX2

PowerModule TM

TX2RX3TX3

RX4TX4

PowerModule TM

- +

P3

P2

P1

PowerModule TM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 34 56 7 89 2

PM1000

175

PM1000

175

RX1TX1

RX2

PowerModule TM

TX2RX3TX3

RX4TX4

PowerModule TM

- +

P3

P2

P1

PowerModule TM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 34 56 7 89 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

158
19

RX1TX1RX2

PowerModule TM

TX2RX3TX3RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

RX1TX1RX2

PowerModule TM

TX2RX3TX3RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

RX1TX1RX2

PowerModule TM

TX2RX3TX3

RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

Regulated

DC bus to

motor drives

CAN

Hub

CAN

Adapter

System 

Controller

Fuel cells

Motor

Drives

RX1TX1RX2

PowerModule TM

TX2RX3TX3RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

RX1TX1RX2

PowerModule TM

TX2RX3TX3RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

RX1TX1RX2

PowerModule TM

TX2RX3TX3RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

RX1TX1RX2

PowerModule TM

TX2RX3TX3RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

RX1TX1RX2

PowerModule TM

TX2RX3TX3

RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

RX1TX1RX2

PowerModule TM

TX2RX3TX3

RX4TX4

PowerModuleTM

- +

P3

P2

P1

PowerModuleTM

PM1000

175

PM1000

175

PRCH

Com

Com

PS Gnd

NO

PS

J4 J3 J1

J16

J2

2 1 2 2 1 2 1 1

1 3456789 2

PM1000

175

PM1000

175

C

L

DC +

DC -

Coil

Aux Cont

Precharge

Contactor

PS AC

or

DC

DC

Protection Anode

Electrolyte

Cathode

Regulated

DC bus to

motor drives

CAN

Hub

CAN

Adapter

System 

Controller

Fuel cells

Motor

Drives

PM1000 PDK Success Story PM1000 PDK Success Story PM1000 PDK Success Story – Fuel Cell Bus – Fuel Cell Bus Fuel Cell Bus 

20

PM1000 System Developer Kit PM1000 System Developer Kit PM1000 System Developer Kit – SDK

CAN

Hub

Fiber Optic I/O

PM1000

CAN

Bridge 

n = 1

n = 2

n = 30

Ethernet 

Connector

Active Rectifier

DC-DC

AC Voltage Source

Motor Control

CSPS (IP) Active Rectifier

DC-DC

AC Voltage Source

Motor Control

CSPS (IP)

Active Rectifier

DC-DC

AC Voltage Source

Motor Control

CSPS (IP)

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

159
21

PM1000

PM1000

PM1000 SDK PM1000 SDK PM1000 SDK – Custom S/W & User Programmability – Custom S/W & User Programmability Custom S/W & User Programmability

• Series and/or parallel 

PM1000s

• Master DSPA

• DSPB with Customer 

Specific Proprietary

Software (CSPS)

• Laptop with GUI

- Configure PM1000s

- Monitor

- Download software

• System level controller with 

customer software

PM1000

PM1000

DSPA

MASTER

CAN HUB

DSPB with

CSPS (IP)

System Controller

Laptop with GUI

DSPA DSPB with

CSPS (IP)

DSPA DSPB with

CSPS (IP)

DSPA DSPB with

CSPS (IP)

22

PM1000 SDK PM1000 SDK PM1000 SDK – Wind Turbine Application – Wind Turbine Application

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

Ethernet 

Connector

CAN

Adapter 

Active Rectifier Active Rectifier

DC-DC

AC Voltage Source

Motor Control

AC Voltage Source

DC-DC

Active Rectifier

Motor Control

AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

CSPS (IP) CSPS (IP)

CSPS (IP)

160
23

PM1000 SDK PM1000 SDK PM1000 SDK – Wind Turbine Application – Wind Turbine Application

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

Ethernet 

Connector

CAN

Adapter 

Active Rectifier AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

1050VDC

CSPS (IP)

24

PM1000 SDK PM1000 SDK PM1000 SDK – Wind Turbine Application – Wind Turbine Application

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

Ethernet 

Connector

CAN

Adapter 

Active Rectifier AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

1050VDC

CSPS (IP)

Fiber Optic I/O

PM1000 Active Rectifier

Motor Control

Active Rectifier

CSPS (IP)

AC Voltage Source

DC-DC

Fiber Optic I/O

D-VAR®

161
25

PM1000 SDK PM1000 SDK PM1000 SDK – Wind Turbine Application – Wind Turbine Application

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

Ethernet 

Connector

CAN

Adapter 

Active Rectifier AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

1050VDC

CSPS (IP)

Fiber Optic I/O

PM1000

Active Rectifier

Fiber Optic I/O

D-VAR®

26

PM1000 Wind Turbine & Fuel Cell Application

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

Ethernet 

Connector

CAN

Adapter 

Active Rectifier AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

1050VDC

CSPS (IP)

Fiber Optic I/O

PM1000 DC-DC

Motor Control

DC-DC

CSPS (IP)

AC Voltage Source

Active Rectifier

Fiber Optic I/O

162
27

480VAC

60 Hz

PM1000 SDK PM1000 SDK PM1000 SDK – Fuel Cell UPS Application – Fuel Cell UPS Application

750VDC

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

System 

Controller

CAN

Adapter 

Active Rectifier AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

CSPS (IP)

Fiber Optic I/O

PM1000

DC-DC

Fiber Optic I/O

Anode

Electrolyte

Cathode Membrane

H2

Cathode

Anode

Electrolyte

28

PM1000 SDK PM1000 SDK PM1000 SDK – Fuel Cell UPS Application – Fuel Cell UPS Application

750VDC

Fiber Optic I/O

PM1000

Fiber Optic I/O

PM1000

CAN

Hub

CAN

Adapter 

Active Rectifier AC Voltage Source

Fiber Optic I/O Fiber Optic I/O

480VAC

60 Hz CSPS (IP)

Fiber Optic I/O

PM1000

DC-DC

Fiber Optic I/O

Anode

Electrolyte

Cathode Membrane

H2

Cathode

Anode

Electrolyte

System 

Controller

163
29

PM1000 SDK PM1000 SDK PM1000 SDK – Fuel Cell UPS Application – Fuel Cell UPS Application

750VDC

Fiber Optic I/O

PM1000

CAN

Hub

CAN

Adapter 

AC Voltage Source

Fiber Optic I/O

480VAC

60 Hz CSPS (IP)

Fiber Optic I/O

PM1000

DC-DC

Fiber Optic I/O

Anode

Electrolyte

Cathode

Heat

Water

Air

480VAC

60 Hz

Membrane

H2

Cathode

Anode

Electrolyte

System 

Controller

Fiber Optic I/O

PM1000

Active Rectifier

Fiber Optic I/O

30

PM1000 2MW Generator Set Application

164
31

PM1000 Distributed Generation PM1000 Distributed Generation Applications Applications Applications

Wind Turbine

PM1000 provides power flow 

control of the wind turbine’s 

output.

Fuel Cell

PM1000 used to provide a 

regulated output voltage 

from the fuel cell.

Generator Set

2MW gen-set using a high 

speed alternator and 

PM1000 for UK Ministry of 

Defense naval applications.

32

PM1000 Distributed Generation PM1000 Distributed Generation Applications Applications Applications

Wind Turbine Solar Microturbine

Wind Turbine Fuel Cell Fuel Cell Gen. Set

165
33

PM1000 Distributed Generation PM1000 Distributed Generation Applications Applications Applications

Fuel Cell Fuel Cell

Wind Turbine Solar

Gen. Set

3-Phase AC

34

PM2000

166
THE POWER IN

POWER TECHNOLOGY

Modular Inverters

for Distributed Generation

Matthew Zolot

UQM Technologies

Presented at the Advanced Power Electronics 

Interfaces for DE Workshop

August 24th, 2006

THE POWER IN

POWER TECHNOLOGY

Outline

3⁄4 UQM Specialization

3⁄4 Functional Specifications

3⁄4 Design for Modularity

3⁄4 System Integration Issues

167
THE POWER IN

POWER TECHNOLOGY

Company Overview

UQM Technologies is a technological leader in the 

development and manufacture of very high performance, 

power dense and energy efficient:

 electric motors

 generators

 power electronic controllers 

for vehicle electrification.

THE POWER IN

POWER TECHNOLOGY

Electrification of Engine-Driven Auxiliaries

3⁄4 Easily adapted, non-disruptive

3⁄4 Improved controllability

3⁄4 Improved reliability

3⁄4 More easily serviced

3⁄4 Flexible architecture

3⁄4 Available export power

3⁄4 Key strategy to meet diesel 

emission mandates

3⁄4 7-15% improvement in fuel 

economy

DC – DC 

Converter

Cooling pump

Electric Oil Pump

Compressed Air 

Module

DC – AC 

Inverter Modular HVAC

Cooling fan

High Power 

Generator

168
THE POWER IN

POWER TECHNOLOGY

UQM Core Competencies

3⁄4 UQM products have technology 

advantages over conventional 

systems

 Power density

– smaller and lighter weight

 Efficiency 

– consume less energy

 Performance

– eliminate gearing

– adaptive software control

 Rugged

– automotive & military grade

packaging

Competitor

Traction system motors

Competitor

Traction system controllers

THE POWER IN

POWER TECHNOLOGY

Motor Controller Example

CD40-400L Controller

3⁄4 DC to AC 3-phase motor / 

generator controller (4 

quadrant)

3⁄4 140 kW maximum input 

(350 VDC, 400 ADC)

3⁄4 380 x 365 x 120 mm 

dimensions

3⁄4 16 kg weight

3⁄4 Liquid (water/glycol) 

cooled

UQM’s experience with small, 

lightweight vehicle electronics 

helped us win this SBIR award

169
THE POWER IN

POWER TECHNOLOGY

Outline

3⁄4 UQM Specialization

3⁄4 Functional Specifications

3⁄4 Design for Modularity

3⁄4 System Integration Issues

THE POWER IN

POWER TECHNOLOGY

Bringing Unique Perspective to DG

3⁄4 Plug-in varieties of Hybrid 

Electric Vehicles are getting a 

lot of attention these days.

3⁄4 Automotive requirements for 

DG products will differ from 

stand-alone implementations.

- High voltage

- High density

- Light weight

- High efficiency

- Rugged packaging

&

- Low Cost (key to 

automotive)

UQM DG Inverter Specifications:

3⁄4 Vin: 150 – 360 V

3⁄4 Pout: 250 – 5000W (3 - 1.7kW 

modules)

3⁄4 Efficiency: >90%

3⁄4 Galvanic Isolation

3⁄4 Grid & Stand-alone operation, 

50/60 Hz

3⁄4 Standards: UL 1741, IEEE 

1547, IEEE 519

170
THE POWER IN

POWER TECHNOLOGY

Grid DG 

Terminal

Aux

Load Terminal

Grid DG 

Terminal

Aux

Load Terminal

FB Rect Filt

=

Caps Filt

Overall Layout

THE POWER IN

POWER TECHNOLOGY

Automated Control Code Generation

Mathworks Autocoding with DSP platforms

3⁄4 Existing and customized MATLAB blocks are 

used selectively to quickly develop new systems

3⁄4 Popular Mathworks platform leveraged for 

system simulation

3⁄4 Embedded safety features

3⁄4 OEM configurable parameters

3⁄4 Successfully used within 

several development programs

171
THE POWER IN

POWER TECHNOLOGY

True Sine Wave AC Generation

Texas Instruments DSP platforms

3⁄4 Enables the use of advanced signal processing

3⁄4 PWM based True Sine wave generation

3⁄4 Software configurable for split-phase, in-phase, 

& 3-phase operation

THE POWER IN

POWER TECHNOLOGY

Outline

3⁄4 UQM Specialization

3⁄4 Functional Specifications

3⁄4 Design for Modularity

3⁄4 System Integration Issues

172
THE POWER IN

POWER TECHNOLOGY

Modular Inverter – Design Trade-offs

+ =

3⁄4 Higher component integration levels 

vs. discrete components on FR4

- Highly dependant on operating 

specifications (P, I, V)

- Cost (top priority for Automotive)

- Packaging density

- Performance (High frequency, 

inductance, trace lengths, etc.)

3⁄4 Level of Modularity {PEBB}

- Component Level

- Board Level

- Package Level

THE POWER IN

POWER TECHNOLOGY

Modular Inverter – Initial Design (Base Package)

6 in.

8 in.

8 in.

5 in.

DC-DC module 8x8x8” Inverter modules 8x8x5” respectively

3⁄4 High frequency, Isolated DC-DC front end: 5kW

- Capable of stand-alone operation

3⁄4 Modular Inverter (up to 3 modules, each 1.7kW)

3⁄4 Liquid Cooled (automotive variety)

173
THE POWER IN

POWER TECHNOLOGY

Modular Inverter – Interconnection Potential

1.67 kW Inverter 5 kW Inverter 10 kW Inverter

3⁄4 Sub-Block Modularity

- 1.7 kW, 3.4 kW, or 5 kW at 120/240 VAC 60 Hz single phase, or 5 kW 

3-phase

3⁄4 Block Modularity

- 5 kW, 10 kW, etc... operation

THE POWER IN

POWER TECHNOLOGY

DC/DC DC/AC DC/AC DC/AC Load

120 Split Phase Arrangement 240 Arrangement

3φ Y Arrangement 3φ Δ Arrangement

DC/DC DC/AC DC/AC DC/AC Load

120∠0° Hot OR 240 Hot

120∠0° & 120∠180° Neutral

120∠180° Hot OR 240 ‘Neutral’

Terminals

DC/DC DC/AC DC/AC DC/AC Load DC/DC DC/AC DC/AC DC/AC Load

Functional Modularity

174
THE POWER IN

POWER TECHNOLOGY

Outline

3⁄4 UQM Specialization

3⁄4 Functional Specifications

3⁄4 Design for Modularity

3⁄4 System Integration Issues

THE POWER IN

POWER TECHNOLOGY

Challenges to Going Modular

3⁄4 Goal: prevent redesign/modifications for every unique 

implementation

- Enable higher volumes and reduced costs

Challenges:

3⁄4 Evaluate mechanical connections for all types of terminal 

requirements (Input & Output)

3⁄4 Communication: between modules & packages

3⁄4 Anti-Islanding: Identification and prevention

3⁄4 New market: will the egg grow into a Chicken?

175
THE

POWERIN

POWERTECHNOLOGY

Questions?

176
Power Electronics Conversion for 

Distributed Energy Applications

By: Dr. Alex Levran

EVP & CTO, Magnetek Inc

CEC & NREL

www.alternative-energies.com

Overview:

• Technology

• Applications and Products

– Wind

– PV

– Variable Speed 

– Energy Storage

– Fuel cells

• Future Trends

177
Magnetek Inc - Fast Facts

Headquarters: Los Angeles, CA (USA)

Listed on NYSE, ticker MAG

Sales >$250M 

1,500+ Associates worldwide

7 plants in Europe, North America, Asia

Core Technology: Power Electronics Conversion

Embedded products and Systems

Distributed Energy Technologies

• Wind 

– Large farms compete with central generation

– Residential applications <10kW

• Photovoltaic

– Growing Commercial and residential applications.

– Lower cost materials and manufacturing processes for PV panels 

key to increased market penetration

• Energy Storage

– Full range of batteries, flywheels and ultra-capacitors evolving for 

managing transients, compressed air,SMES

• Fuel Cells

– Automotive applications key to small-scale FC economics

– Limited success in commercial and telecom

• Variable Speed Generation

• Microturbines

– Lower cost, higher reliability critical for market expansion

178
Power Electronic Conversion -

Requirements

• Grid Connection

– Anti Islanding, kVAR control, Unbalance/Nonlinear Loads

– Low and medium voltages

– Power Quality and Harmonic Distortion (IEEE 519) 

– IEEE 1547 Standard for Interconnecting Distributed 

Resources with EPS. 

– DC current injection (w/o transformer)

• Higher Efficiencies

– Power Conversion

– Energy Harvesting

• Mechanical Packaging

– Parallelable, scalable designs 

– Indoor and outdoor applications

– Thermal management : air and liquid cooling

– Compact designs, higher power densities 

• Improved Reliability

• Cost competitiveness

• Communication and Remote Monitoring

– Power Line and/or RF Communication

– SCADA and GIS interfaces

Power Electronic Inverters Technology

• Converters/Inverters Topology:

– Voltage source for stand alone. Current Source for grid 

connected operation

– Sinusoidal PWM,multi(three) level or space vector 

modulation. 

– Low or high frequency galvanic isolation

– Non-controlled and active rectifiers. Buck /Boost 

Converters.

– Unidirectional and bidirectional architectures/operations.

– System integration configurations: cascade inverters, 

cascade rectifiers, cascade total conversion systems

• Control Circuits and Algorithms (digital):

– Voltage, Current and Frequency Control 

– Power Flow Control

– Real and Reactive Power Sharing 

– Protection Circuits 

• Local and Remote Communication Protocols 

(supervision, controls, and monitoring) 

179
Photovoltaic 

Systems

• High reliability and efficiency 

power converters

• Primary energy source control 

• Grid interface know-how (grid 

tied, stand alone, hybrid)

• High power density and 

compact size

• System level control

• Modular design for multiple 

sources (PV, wind,FC).

• Scalable design. common 

building blocks & platforms

Strategy: To lead the market of power electronic 

interfaces for alternative energy systems.

Wind 

Generators

Fuel Cell 

Microturbines Systems

and Variable 

Speed 

Distributed 

Generation

COMPLETE POWER INTERFACE FOR SMALL POWER 

WIND SYSTEMS

• Up to 10kW

• Most compact design available on the market

• Stand Alone and Grid-tied operating modes

• Optional Photovoltaic and Genset inputs

• Split phase inverter for worldwide 110V/60Hz or 

220V/50Hz operation

• Aurora PV platform with minor change.

• Parallelable.

• Advanced communication 

POWER CONVERTER FOR LARGE POWER 

WIND SYSTEMS

• Up to 3.0 MW

• DSP based digital control

• Parallel multiple 625 kW inverters

Wind Power Conversion

180
D C /D C B oost C onverter G rid Interface Inverter

G ate D rive Board G ate D rive B oard

Inverter

Embedded

C ontroller

Inverter

Embedded

C ontroller

Line Filter

Grid Interactive Inverter System for Sm all W ind Turbine

Electrical and C ontrol B lock D iagram

Operator

Interface

T o

D istribution

P anelboard

Breaker

Inverter Current Feedback

G rid V oltag e F ee dback

DC Current Feedback

Optoisolation

PMSG

Aurora W ind

Inteface Box

2 - line LC D R eset

20 A

3.6 kW

K 1

CB1 H igh Vo ltage D C Bu s

PMG

input

V o c = 400 V m ax.

V nom = 360 V nom.

V min = 40

G e nerator V oltag e F ee dback

Load Bank

(O ptio nal)

20 A

A urora W ind Inverter

3.6 kW

Small Power Wind Inverter Topology

• Typical Characteristics:

– Output Voltages: Low to medium 

– Grid Connection: UL1741 or Stand Alone

- Indoor and outdoor designs. Air and water cooled designs.

• Topology:

– Full bridge rectifier 

– Voltage fed three phase inverter with adjusted current 

– Three Level Inverter or Space Vector Modulation 

– Bi-directional conversion for doubly fed generators.

• Features:

– High efficiency (>97%)

– Low THD meets IEEE 519

– Modular and scalable designs

– Enhanced voltage regulation 

– Compact design

– Advanced communication

– Closed loop controls with the turbine

Large Power Wind Turbine Inverter

181
Notes:

1. Dash ed lines in dicate custom er su pplied w irin g.

2. PM synchronous generator by Custom er.

3. D en otes dem arcation betw een cu stom er-su pplied and factory-installed w iring .

G rid Interface Inverter

G ate D rive B oard

PCU

Embedded

C ontroller

PCU

Embedded

C ontroller

Line

Filter

G rid Interactive VSC for W indturbine

Electrical and Control Block Diagram

To 690 VAC G rid

3-wire O utput

Inverter Current Feedback

Grid V oltag e F ee dback Generator Voltage/Frequency Feedback

PMG

Generator Rectifier

2320 A

2.5 MW

K 2 K 1 CB1

1400 VDC Bus

DC Choke

(Generator Dependant)

TCU

C ontroller

G enera tor C urren t Fe edba ck

Fiber O ptic

Fiber

Large Power Wind Turbine Inverter 

0

EMI

filter

UTILITY GRID

EMIFILTER

FUSE

IGBT

BREAKING

DRIVING BOARD

DESAT IGBT

DSP BOARD CONTROL

AND ANTI-ISLANDING)

OPTICAL FIBER

OUTPUT INTERFACE 

AND IEEE485

OPTICAL FIBER

GROUND FAULT SENSING

AUX POWER 

SUPPLY

AUX 

POWER

720-800V BULK

VOLTAGE

PMG

Three Phase Bridge VSC Topology

182
Three Phase Tri-level Inverter 

three level

inverter

three level

inverter

three level

inverter

4.2KV 60Hz to

isolating

transformer

filter

capacitors

High

speed

generator

Three Level Inverter

Large Power Wind Turbine Inverter(>2.5MW)

183
Advantages of Large Wind PMG Turbine- Up to 5.0 MW

Variable Speed Converter (VSC) Value Proposition

Advantages of Full Scale Conversion with PMG (Permanent Magnet Generator):

. 

Increase efficiency of 7 1/2% over wound rotor technology for 

variable speed:

• PMG Generator 3% more efficient than the Wound rotor 

induction generator

• PMG is 1/3 the size and cost

• Gear box 1/2 the size and cost, while 2% more efficient

• Converter is 2 1/2 % more efficient and 1.5 x cost

• Wound rotor systems in the 2 MW range are $.047 kWh vs.

$.032 kWh with Full conversion utilizing PMG

• Avoids infringements of current IP 

• No brushes as with wound rotor generators for higher reliability

. 

• Up to 6000W

• Top level performance

• Indoor and Outdoor 

models

• Advanced remote 

communications

Photovoltaic Power Conversion

AURORA 

PHOTOVOLTAIC 

INVERTERS

184
• Topology:

– Single or multi-string conversion 

– Typical Architectures:

• Boost converters with DC link and PWM full bridge inverter with or without low 

frequency transformer isolation (grounded PV panels)

• Single inversion stage with low frequency transformer for galvanic isolation and 

voltage adjustment. 

• Typical Performance:

– Power Ratings: 500W to 8000W 

– Wide open circuit voltage range from 90VDC to 600VDC

– High efficiency: Exceeding 96%

– Cost competitive, high power density design

– Harmonics: meets IEEE 519 spec

– Grid connected operation: Meets UL 1741 and VDE requirements.

– High overload capabilities, operates at high temperatures, and anti-islanding 

protection

– Packaging: Indoor meets Nema2(IP21) and outdoor meets Nema4(IP65) 

– Advanced local and remote communications and continuous data logger

Residential Photovoltaic Inverters

Optimal Performance

Aurora higher power models are Multistring inverters with two 

independent and fast Maximum Power Point Tracking (MPPT) inputs

PV Array

Voc = 600 V max.

Vnom = 340 V nom.

Vmin = 150 Vmin.

+

+

-

-

Booster DSP control

EMI

and

protections

Booster 1

Booster 2

185
Commercial PV Inverter 

• Topology:

– Full Bridge with PWM or multilevel controls and topologies.

– Parallel-able with advanced master/slave assignment algorithm 

• Typical Performance:

– Power Ratings: 30kW to 250kW. 50kW modules

– Wide open circuit voltage range from 300VDC to 600VDC or 400VDC to 900VDC

– High efficiency: Exceeding 97%

– Advanced MPPT algorithm to harvest higher energy

– Cost competitive, high power density design

– Harmonics: meets IEEE 519 spec. Low DC current components.

– Grid connected operation: Meets UL 1741 and VDE requirements.

– High overload capabilities, operates at high temperatures, and anti-islanding 

protection

– Packaging: Indoor meets Nema2(IP21) and outdoor meets Nema4(IP65) 

– Advanced local and remote communications and continuous data logger

– Output transformer section (low frequency, low and medium voltages)

Commercial Photovoltaic Inverters

186
• Typical Characteristics:

– Multi mode operation: Grid Connected, Stand-alone, UPS 

– Universal Inverter: Single phase 230VAC, 110VAC, 50Hz and 60Hz

– Multi Source: Wind, PV (max 420VDC), Gen-sets (115VAC split phase 

230VAC, 10%), batteries (48V/110A or 110V/50A).

• Topology:

– Two stage conversion: DC/DC converter and single phase full bridge 

inverter.

• Typical Performance:

– Power Ratings: 2500W to 6000W 

– High efficiency: Exceeding 90% from renewable source and 92% from 

Battery.

– Cost competitive compact design

– Harmonics: meets IEEEE 519 spec

– Grid connected operation: Meets UL 1741 requirements

– Advanced local and remote communications

Multimode Wind Converters 

Stand-Alone Single Phase Converter 

187
•50kW and 100kW

• Easily Transportable (light and small)

• High Reliability

• High Power Quality

• Reduced emissions

• Cogeneration

• Versatile

Microturbine - Compact Power Generator

COMPLETE POWER INTERFACE FOR FUEL 

CELL SYSTEMS – RESIDENTIAL AND 

AUTOMOTIVE APPLICATIONS

•PCS – 2000W to 7400W

• Stand Alone and Grid-tied operation

• Auxiliary output for start-up phase of fuel cell stack

• Split phase inverter for worldwide 110V/60Hz or 

220V/50Hz operation

Fuel Cell Inverters

COMPLETE POWER INTERFACE FOR 

FUEL CELL SYSTEMS – INDUSTRIAL 

APPLICATIONS

• PCS-3: 300 kW

• Grid tied and stand alone operating 

modes

• MULS (Multiple unit load sharing) up to 

six units

• Seamless transition with optional static 

switch

188
• Typical Characteristics:

– Convert DC output voltage from fuel cell module to three phase AC voltage.

– Supports different fuel cell source technologies: Phosphoric Acid, Proton 

Exchange Membrane, Molten Carbonate, and Solid Oxide. 

• Topology:

– Two stage conversion. Three phase inverter PWM inverter.

– Space vector modulation or sinusoidal PWM 

• Features:

– Indoor or outdoor designs.

– Water cooled or air cooled

– Efficiency over 93%

– Harmonics: meets IEEE 519

– Parallelable, scalable designs

– Connection: stand-alone or grid connected UL 1741

– Remote monitoring an control

Fuel Cell Inverter Technology 

Large Scale Fuel Cell Inverters > 

200kW

• UTC Fuel Cells: 200 kW, (160) 

• Installed base exceeds 32 MW

• Other customers: 300kW modules

Power Conversion

for Fuel Cells

189
• Applications:

– Load Leveling

– Power Quality and Energy Management

– Integration with renewable energy sources for enhanced efficiency 

and higher capacity

• Sources:

– Batteries: Lead Acid, Sodium Sulphur-NAS, Nickel Cadmium(NiCd), Nickel Metal Hydride(Ni-MH), Vanadium Redox (VRB), 

Lithium Ion(Li-Ion)

– Flywheels,Compressed air storage

– Superconductive Energy Storage 

• Typical Topology:

– Bi-directional Two stage conversion: Back/Boost DC Converters 

and PWM Inverters with transformer isolation.

• Performance Features and Controls:

– Power range: 200kW to 10MW

– Charging/discharging control algorithms to extend battery life

– High efficiency

– Low harmonic distortion

Energy Storage Converters

Energy Storage Converters 

PCS Remote 

Controller

&

Comm. Unit

190
• Inverter Technology:

– New Topologies (tri-level inverters) and improved control 

algorithms.

– Higher voltage and current rating of IGBTs, and SiC components.

– Improved thermal management devices (heat-sinks, 

– Improved driver and sensing circuits(fiber optical)

– Improved capacitors and magnetic devices

– Will drive:

• Higher conversion efficiency, higher power density, higher reliability

• Higher voltage (Medium), higher power, lower cost 

• Expansion of Modular designs:

– Flexibility of installation and application

– Scalability

– Multiple sources of energy, similar platforms (Topologies) 

• Improved Communication:

– Enhanced maintenance and service

• Hybrid Systems:

– Combination of PV and Wind with advanced energy storage devices 

for better power quality and back-up power applications

Future Trends (>3years)

191
Xantrex Power Electronics for 

Renewable Energy System Applications

Ray Hudson

Vice President Advanced Technology

ray.hudson@xantrex.com

2

• Xantrex Overview

• Renewable Energy Power Electronic Converter 

Products

• Residential Solar – Grid Tied

• Residential Solar – Off-Grid/Backup

• Industrial/Commercial Solar – Grid Tied

• Wind

• Others

• Future Direction

Outline

192
3

Xantrex Overview

Offices

Manufacturing

Employees

Revenue

Patents

Ownership

Established

Livermore, CA, San Luis Obispo, CA, Burnaby BC, 

Arlington WA, Elkhart IN, Barcelona Spain, 

Reading England, Beijing China

Livermore CA, Burnaby BC, Arlington WA, 

Dominican Republic, China (4 Outsourced 

Locations)

500

US$143 Million in 2005

79 patents with 97 more in progress 

Public, Traded on Toronto Stock Exchange (XTX)

1983

4

ADVANCED POWER ELECTRONICS Target Markets

Renewable Power Renewable Power

Portable & Mobile 

Power

Portable & Mobile 

Power

Programmable Power Programmable Power

193
5

Mobile Power – Product Portfolio

Mobile Power

Recreational Vehicles

RS2000/MS2000

Inverter/Chargers 

Xantrex Battery

Chargers

Freedom Marine 458

Inverter/Chargers 

TrueCharge 

Chargers 

Prosine

Inverters & Inverter/Chargers 

Commercial Vehicles

Railmount

Inverter/Charger 

Fleetpower

Inverter/Chargers 

Prosine

Inverters & Inverter/Chargers 

Portable Power

XPower Powerpack 300

Micro Inverters 

XPower Plus Inverters 

XPower Chargers

XPower Jumpchargers

XPower

Powerpack 150 

XPower

Powerpack 400

6

Programmable Power – Product Portfolio

Design & Development

XFR 1.2 – 2.8kW

Full Rack Programmable

DC Power Supply

XDC 6-12kW

Digitally Controlled Programmable

DC Power Supply 

Value Line (XDL, XPF, XPL, XPH)

Digitally Controlled Programmable

DC Power Supply 

Manufacturing Test

XFR 1.2 – 2.8kW

Full Rack Programmable DC

Power Supply

XHR

Half Rack Programmable 

DC Power Supply 

XPD

Quarter rack Programmable

DC Power Supply

Precision Equipment

XDC 6 – 12kW

Digitally Controlled Programmable

DC Power Supply

XMP

Multiple Output Programmable 

DC Power Supply

XT

Quarter rack Programmable 

DC Power Supply

Programmable Power

194
7

Renewable Power Examples

Wind

1.5 MW Converter

Industrial Wind

10 kW Grid Tech Inverter

Small Scale Wind

Backup

DR

Inverter/Charger

SW Plus

Off-Grid Backup Power 

Inverter Charger 

Solar

PV Series

10 kW to 225 kW 

NA 3 Phase 

Commercial Grid Tie

GT100E

Int’l 3 Phase 

Commercial Grid Tie

SW Plus

Off-Grid Inverter/Charger 

GT Series

Residential 

Grid-tie Inverter 

GT500E

Int’l 3 Phase Commercial Grid Tie

SW Power panel

Off-Grid Backup Power 

Inverter Charger 

8

•Convert DC from PV Array to AC

• Grid Connected Inverters

• Only source power to utility grid

• Off Grid/Backup Inverters

• Include storage for operation when grid not 

available

•Charge Controllers for battery interfacing

• Often included in “Balance of System”

• Is a very key system component

• User interface

• Implements safety features

• “Heart and Brain” of the system

• Sometimes viewed as system weak link

Power Electronics for Solar Applications

195
9

Battery Based Inverters Single Phase Grid Tie

DR Series

PV Series

10 kW to 225 kW 

NA 3 Phase 

Commercial Grid Tie

GT Series

Residential 

Grid-tie Inverter

SW Series 2.5 to 3.8 kW 

3-Phase Grid Tie

SW Plus Series

Solar Portfolio 

10

• True 2.5kW, 3kW, 3.6kW power 

rating

• High efficiency (CEC 94.5%)

• Wide PV DC MPPT range

• Faster and less expensive to install

• Light weight and compact

• Integrated DC/AC disconnect

• Wiring box

• Split chassis design (easy to service)

• Communications: 

• LCD display 

• Communication ports and software

• Attractive industrial design

• Passive cooling

• Demonstrated reliability

GT3 Series Residential 

Grid Tied Inverter Features

196
11

• High frequency design

• Reduces copper losses

• Smaller, lighter magnetic components = compact/low 

weight

• Uses new, state-of-art power devices

• Takes advantage of newer/more advanced 

semiconductors

GT 3 Design Topology

12

SW Series

• Off Grid / Primary Power

• Backup Power

• Sell PV power back to utility 

/ provide backup power

• Battery charger standard

• Sine wave output power

• Low frequency design 

topology

• 2.5, 4.0 & 5.5 kW 120 VAC 

60 Hz

• 3.0 & 4.5 kW 230 VAC 50 

Hz

• Most features of any 

inverter in the world –

complex, but many variable 

programming options

• Over 30,000 sold worldwide

197
13

DR Series

• Off Grid / Primary Power

• Backup Power

• Battery charger standard 

• Modified sine wave output 

power

• Low frequency design 

topology

• 1.5, 2.4, 3.6kW 120 VAC 60 

Hz

• 1.5, 2.4 230 VAC 50 Hz

• 12 & 24 Volt

• High Surge Capacity

• Simple to install and use

14

C Series Charge Controllers

• Interface between DC and 

battery for charging

• 12, 35, 40, or 60 amps

• Solid state, electronically 

controlled, pulse width 

modulated (PWM) controllers

• Stand-alone lighting system 

controller (C12)

• Charge and diversion 

controllers (C35, C40, and 

C60)

• Optional temperature 

compensation

• Adjustable charge control set 

points 

• Rugged & reliable

198
15

PV Series Product Overview

• Three-phase grid connect PV inverter for 

commercial, industrial and utility scale 

applications

• Three product platforms comprising 10 

distinct models

• Single Stage DC to AC Inversion

• Single, “central” inverter minimizes 

installation and maintenance costs in large 

commercial applications

16

Real-World Installations

PV150 (34) 5.1MW - Tucson Electric Power

99.92% Inverter Availability in 2005

199
17

Key Requirements

Xantrex 

High efficiency • Maximizes rebates and minimizes PV 9

Sealed design • No external contaminants, no filters to clean, 

higher reliability 9

Communication capabilities • Flexible options including free GUI to maximize 

uptime 9

Low part count • Better reliability and maintainability 9

Low weight • Easier to transport and install 9

AC Disconnect on transformer output 

and soft start circuit • Reduce tare loss and transformer inrush 9

 Wide MPPT Voltage Range • Covers all temperature conditions and module 

types 9

Negative & Positive Ground Arrays • Allows use with positive ground modules 9

FCC Part B compliant • Less potential interference with communication, 

radio, and consumer electronics 9

Meets all applicable codes including 

UL1741 and IEEE 1547 • Inverters can be installed in any jurisdiction 9

18

•Convert variable frequency and Voltage AC 

from generator to grid compitible AC

•Commercial scale – MW

• Typically installed in North America in large 

“windplants” – similarities to central generation

• Ride-Through – FERC requirements

• Communications – utility SCADA

•Small Wind <30KW

• Residential

• Systems sometimes incorporate storage for offgrid or backup applications

Power Electronics for Wind Applications

200
19

Line

Filter

Utility Inverter Generator Inverter 

G

Utility 

(480/690 V)

Line Current Control Generator Control

Induction

Generator

Xantrex Converter Technology

For Induction Generator

Variable Voltage

And Frequency

DC

20

Xantrex Wind Converter Products

410kW Windturbine

and Converter

33 Meter Blade 

Diameter

201
21

Xantrex Wind Converter Products

750kW Windturbine

and Converter

50 Meter Blade 

Diameter

22

Xantrex Wind Converter Products

1.5MW Windturbines

and Converter

70 Meter Blade 

Diameter

202
23

Xantrex Wind Converter Products

2.5MW Windturbine

and Converter

93 Meter Blade 

Diameter

24

• Xantrex has Experience with Power Electronics 

for other Distributed Energy Resource 

Applications

• Fuel Cells

• Microturbines

• Advanced Energy Storage 

• Flow Batteries

•Superconducting Magnetic Energy Storage

• Fly Wheels

• Large Hybrid Systems

•Relatively small volumes 

•Xantrex approach is to leverage from wind 

and solar

Power Electronics for Other DER 

Applications

203
25

Xantrex R&D

• Internal development activities

• Wind is OEM product designed for each turbine

• Advanced solar products

• Other DER applications based on practical business 

case

• Sandia High Reliability Inverter Program 

• Residential Solar inverter incorporating storage

• NREL PV Manufacturing R&D Program

• 500kW Solar Grid Interactive product

• We support DOE Systems Driven Approach and 

Solar America Initiative goals

• Goal of reducing cost of energy ($/kWhr) is key!

26

Future DER Power Electronics Direction

•Optimal SYSTEM design

•Including “Balance of Systems”

components 

•Higher Performance Systems

• Higher Reliability

• Higher Efficiency

• Longer Life

• Lower Levelized Cost of Energy (LCOE)

• Easier Installation

•CEC leading in setting high expectations for 

system performance requirements

204
27

Future Direction

•Support for Higher Penetration Levels

•Wind must meet FERC interconnect standards

•Wind – Ride Through and Grid Support (VARS) 

•Solar UL 1741 and IEEE 1547

•Solar – Anti-Islanding and Unity Power Factor

• Likely to come together 

•Other DG sources will follow – eventually

•Possibility to move to “Feed-In Tariff” incentive 

model in US more broadly

• Maximize Energy Delivered (kWHrs)

• Incentive to optimize all system elements

28

Thank You!

205
Power Electronics for DER & Renewable Applications

Northern Power Systems

CEC DE Workshop

August 24, 2006

2 © 2006

Northern Power Systems 

• Subsidiary of Distributed Energy Systems (DESC) 

• High reliability power systems, products, and services

• 225 employees

• HQ and manufacturing facilities in Vermont

• Regional domestic and international offices for sales 

and service 

206
3 © 2006

Northern Power Business Segments

• Distributed Generation

• Commercial

• Industrial

• Remote power systems

• Oil & Gas

• Industrial infrastructure

• Village Power

• Renewable power systems

• Wind

• PV

• Biofuels

4 © 2006

Northern EPC Approach

207
5 © 2006

Power Electronics for DER Applications

Drivers for increased PE use

• New DER technologies require PE interface

• DC, variable speed, non 50/60Hz generation and storage 

devices

• Use of advanced PE enables additional features and 

value across applications

• Standardized interface for simpler interconnect approval

• Advanced power system architectures

• Utility distribution system support

• Increased DER ancillary support capabilities 

• Increased DER penetration levels on distribution system

6 © 2006

Northern’s Power Electronics Focus

• Flexible power converter platform for multiple markets 

• MW Wind

• DER generation and storage assets

• Utility support

• Control capabilities to enable advanced architectures

• PowerRouter® control system

• Family of products to support advanced power systems

• Fast DER switch for critical load support and microgrid 

applications

• Site and fleet level energy management systems 

208
7 © 2006

FlexPhaseTM Power Converter Platform

Developed for wind and DER markets

• Modular converter system for 500kW to 

multi-MW applications

• Liquid and air cooled versions

• 480Vac, 690Vac versions

• Rack-in power modules 

• Configurable power modules

• DC-AC, AC-DC, DC-DC, 

• uni- or bi-directional power

8 © 2006

FlexPhaseTM Power Module Features

• Bi-directional DC-AC or DC to DC power 

conversion

• Small footprint & high power density: 

2.2 kVA/kg (1,956 kVA/m3) liquid cooled

• Flexible universal control architecture

• Include filtering and magnetics

• EMI controlled at module level

• Internal sensing with built in calibration

• Install and extract like draw-out circuit 

breakers

• Low mean time to repair

209
9 © 2006

FlexPhaseTM Converter Platform Applications

10 © 2006

• Modularity

• Configurable for multiple applications and power ranges

• Exchangeable modules for easy service and support

• Low Mean Time To Repair

• High performance

• Full grid support capabilities

− Ride-through, VAR support, harmonic correction

• Very low harmonics (<1%THD capability)

• Reduced stress, longer life for generator and motor windings

• PowerRouter® control system enables microgrid operation

− Peer to peer aggregation of DER generation and storage assets

− No high speed communication required

− Modeless transition between grid & isolated operation 

• Cost

• FlexPhase design allows reduction in power switch costs

• Modular design well suited for reduced manufacturing cost

• Size

• High power density for reduced footprint

FlexPhaseTM Platform Features & Benefits

210
11 © 2006

Northern Current DER Applications

Trend to use PE with conventional DER assets

• Standardized grid interface across applications

• Elimination of fault current contribution

• Simplifies interconnect approval

• Allows interconnection to constrained systems 

• Adds variable speed capability

• Enables advanced power system architectures

• PowerRouter® controls

− Microgrid and critical load support applications

• PowerDistributorTM system

− Interconnect DER asset(s) to multiple service entrances

12 © 2006

MicroGrid Power Network Test System

211
13 © 2006

PowerDistributorTM DER System

Utility

Customer 

Heat Load Customer Electrical 

Service B

Customer Electrical 

Service C

Utility Distribution System 1

Utility Distribution System 2

Customer Electrical 

Service B

Meter

Transformer

Load

Service 

Panel

PowerDistributor

Converters

(each metered service)

Meter Meter

Transformer Transformer

Load

Service 

Panel

Load

Service 

Panel

14 © 2006

DER Utility Interface Switch 

Grid

CB

SA

Bypass

CB

DG

Meas

3

CT

Load

3

3

Com

DSP: Relay + Comm

+ Monitoring/

Diagnostics

• Flexible, universal interface 

for connecting single or 

multiple DER systems 

• Controls for CB, SCR, or 

IGBT switching modules

• Enables

• Critical load support

• Intentional islanding

• Enhanced power quality

• Anti-islanding protection

212
15 © 2006

SmartView® DER Management System

16 © 2006

For more information, contact:

Jonathan Lynch

(802) 583-7224

jlynch@northernpower.com

Northern Power Systems

182 Mad River Park

Waitsfield, Vermont 05673 USA

www.northernpower.com

213
SMA America

Advanced Power Electronics Interfaces Workshop

August 24, 2006

2

Who We Are And What We Do

 Founded in 1981

 Headquartered in Niestetal, Germany

 Approx. 1,200 employees worldwide, 

more than 15 % are engineers

 Technology leader and trend-setter

 Privately held Ag corporation

214
3

Where We Are

 Office recently opened in Korea

4

Product areas

215
5

Synergies of key competence areas

6

US Inverter Products and Applications

 Residential PV, Small Wind, Hydro

 SB1800U, SB2500U 

 SB700U, SB1100U

 SB3300U, SB3800U, SB6000U

 Commercial PV

 SC125U

 Back-up Power and Off-grid

 SI4248U (partially funded by PIER)

 AeroSmart Wind Turbine

 Further expansion of product family by 2007

216
7

Trendsetting Communication Services

 Communication products

 Web Box

– Communication hub and 

system data logger

 Sunny Portal

– Free internet system 

performance server

 Services

 Automated notification of 

performance and system 

alarms.

 Automated performance 

analysis and notification

8

The Future of Distributed Energy

Sunny Island 

4248

Sunny Island 

4248

Sunny Boy Windy Boy

AC

bus

Consumer

Generator

AC coupling: The best solution for flexibility and efficiency of off-grid 

and back-up supplies.

217
9

Design Improvements

 Opti-Cool forced-air cooling

 IGBT skip-packs

 Integrated aluminium 

enclosure and heat-sink

 Ethernet communication

 Load-break rated DC fused 

disconnect

 HALT/HASS testing

10

New Inverter Family Introduction

 Over 98% peak efficiency inverter topology

 Advanced communication and control features

 System performance analysis

 Intelligent off-grid & back-up power integration

 Intelligent three-phase integration to prevent generation 

imbalance

218
11

Recent History in the PV Market

 PV module prices increase 30% in 2 years.

 Inverter competition is high due to PV module shortages.

 IEEE-1547.1 has doubled regulatory certification costs (apr. 

$100,000 per inverter).

 One time CEC rebate system rewards on name-plate ratings 

rather than system performance.

 CEC rebate continues to decline ($2.60 per Watt).

 Copper, steel, specialty metals increased 40% in the last year.

 SB1 passed, rebate may return to $2.80 per Watt.

 CEC Pilot Performance-Based Incentive Program is a step in 

the right direction.

12

Recent History at SMA

 SMA has reduced inverter prices by 20% 

over 2 years.

 Our aim is 5% per price reduction per year.

 Reliability and functionality has dramatically 

improved with new products.

 Advanced communication products 

positioned to:

 Energy reporting for performance based 

incentives.

 REC recording and trading

219
13

Moving Forward

 Shift to performance based incentives

 Define equipment and metering requirements.

 Acceptance of transformerless inverter technologies by AHJ’s

 Immediate adoption of the NEC-2008 Article 690 upon 

publication.

 Ease regulatory requirements

 UL has become a barrier to flexibility, responsiveness and 

innovation.

 Streamline accounting/reporting requirements for PIER funding to

attract established companies.

14

Kent Sheldon

Sales Support Manager

SMA-America, Inc.

12438-C Loma Rica Drive

Grass Valley, CA 95945

530.273.4895 ext 107

www.sma-america.com

220
Appendix E. Additional Resources 

221 
Power Electronics Activities at ISET

Power Electronics for Grid Interfacing

Power Quality

Microgrids

Stand-alone Systems

Dr.-Ing. A. Engler

This presentation gives an overview about ISETs power electronics 

activities with regard to DER and grid integration

222
APEI-Workshop, August 2006, Dr. Ing. A. Engler

2

Modular Systems Technology

Concept, proof of concept

1993 - 1998

Components, control

1998 – 2001

Source: SMA Technologie AG

Interconnection, communication,

protection, EMS, 2001 - 2005

„Modularity“ has been a major topic at ISET for about 15 years!

E. g. within the frame of three national projects a modular concept has 

been developed. A whole DER-component family has been developed 

and transferred to commercial products (SMA). The next step have 

been the integration and interconnection issues.

223
APEI-Workshop, August 2006, Dr. Ing. A. Engler

3

Development of PV- and Battery Inverters

Hardware of PV-Inverter

Hardware of Battery-Inverter

Development of commercial inverters in the kW-range for major PVcompanies as SMA, KACO, etc.

224
APEI-Workshop, August 2006, Dr. Ing. A. Engler

4

Code Generation for Embedded Controllers

Embedded code generation by means of modern development tools 

enabling partially graphical implementation.

225
APEI-Workshop, August 2006, Dr. Ing. A. Engler

5

selfsync®: Droop control for inverters

(patented in Europe and US)

u

u

-1 0 1 Q

QN

u -4%

0

Δ

f

f 0

-1 0 1

-1%

P

PN

Δ f

Frequency droop Voltage droop

The special implementation of droops with the selfsync® algorithm enables

synchronisation and load sharing of inverters without communcation!

Inverters are controlled by droops:

Development of efficient control algorithms especially for stand-alone 

systems and Microgrids.

226
APEI-Workshop, August 2006, Dr. Ing. A. Engler

6

Load sharing and frequency change (selfsync®) 

(file 3_UMRICHTER.pl4; x-var t) t: PV t: PV1 t: PV2 

0.0 0.2 0.4 0.6 0.8 [s] 1.0

0

10

20

30

40

50

60

*103

(file 3_UMRICHTER.pl4; x-var t) t: FR t: FR1 t: FR2 

0.0 0.1 0.2 0.3 0.4 0.5 [s] 0.6

48.8

49.0

49.2

49.4

49.6

49.8

50.0

Loadsharing: contribution depends

on set-point of the idle frequencies

Frequency could be restored by

a secondary control

Selfsync® enables load sharing between inverters bettern than 1 %!

227
APEI-Workshop, August 2006, Dr. Ing. A. Engler

7 „Indirect operation“ of droops in case of resitive

coupling (LV-case)

- Applied droop concept is based on 

inductive coupled voltage sources.

- In a LV-grid components are coupled

resistively, thus voltage determines

the active power distribution

- There are two effects of droops

- direct (inductive coupling)

- indirect (resitive coupling)

- The „indirect“ effect requires droops, 

which have the same sign for the

frequency as well as the voltage droop

and therefore the stable operation point

is „in phase“. f

f0

-1 0 1P

PN

Δf -1%

u

u0

-1 0 1 Q

QN

Δu -4%

Selfsync® is applicable in LV-, MV and HV-Grids!

228
APEI-Workshop, August 2006, Dr. Ing. A. Engler

8 Stability assessment of multi-inverter systems

(selfsync®)

MatLab/Simulink model based on mean

frequency coupling

Stable and unstable 

operating points

Inverters co-ordinated with selfsync® are scalable: One can operate as 

many inverters in parallel as necessary. They can be of different size 

(practically a ratio of 1 : 100 shouldn‘t be exceeded). By special means 

even dynamical loadsharing can be ensured.

229
APEI-Workshop, August 2006, Dr. Ing. A. Engler

9

Electronic switch: possible faults (selfsync®)

-300

0

300

400 420 440 460 480 500 520 540 560 580 600

-100

-80

-60

-40

-20

0

20

40

60

80

100

400 420 440 460 480 500 520 540 560 580 600

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

vMicroGrid [v]

grid connected island

IMicroGrid [A]

time [ms]

 IGrid [A]

Selfsync® masters all possible grid faults, even near short circuits. A 

fast disconnection device is required.

230
APEI-Workshop, August 2006, Dr. Ing. A. Engler

10

High Impedance Grid fault (selfsync®)

Grid

Isolated

Grid

i_USV

i_Load

no transition!

Principally the suggested control mode also continuous operation even in 

case of a line interruption. A grid failure mostly results not in an interruption but in a short-circuit and therefore motivates the development

of a disconnection device!

As the operation mode is not changed between island und grid 

operation, there is almost no transition time.

231
APEI-Workshop, August 2006, Dr. Ing. A. Engler

11

Increasing short circuit power (selfsync®)

Single phase inverter grid

(DeMoTec, ISET)

Short circuit:

triggering a circuit breaker

Standard protection devices can be used with Selfsync® .

232
APEI-Workshop, August 2006, Dr. Ing. A. Engler

12

Parallel operation of an ASG and Sunny Islands

(selfsync®)

Single phase genset with ASG and

capacitor (Fa. Kirsch)

Synchronising a Sunny Island onto

the genset (idle frequency set for 

charging)

Load sharing between Sunny Island and genset is possible due to the

inherent frequency / active power characteric of the genset (slip, mechanical 

controller)

Selfsync® is compatible with standard diesel gensets.

233
APEI-Workshop, August 2006, Dr. Ing. A. Engler

13

Rapid prototyping of 100kVA inverter control

dSpace System

interfaces

ISET develops advanced control algorithms for 100 kVA to 1 MVA 

inverters.

General Advantages of „Rapid Prototyping“:

• Control algorithms are developed using MatLab/Simulink simulation

software. Tested and working models can directly be used in the

prototype.

• Automatic code generation for the architecture of the RapidPrototyping-System.

• Integration of custom C-code possible

• Quick and effective development even of advanced control algorithms

due to high computing power of the Rapid-Prototyping-System.

• Online visualization of all variables

• Adjustment of variables i.e. controller parameters during operation

234
APEI-Workshop, August 2006, Dr. Ing. A. Engler

14

Development of Power Quality Equipment

with rapid prototyping

Prototype, 3.3 kVA, 16 kHz switching frequency, usable energy storage 470 Ws

Distorting load,

Dimmed light bulbs

Power Quality

Monitoring equipment

External interface board of the 

Rapid-Prototyping-System

Host PC with

integrated

Rapid-Prototyping

-System

Realised functions:

• Voltage dependent supply of reactive power (Q droop)

• Dynamic reactive power compensation of dedicated loads

• Dynamic harmonics compensation of dedicated loads

• Flicker reduction

•Local improvement of voltage quality by inductively decoupled subnetworks

235
APEI-Workshop, August 2006, Dr. Ing. A. Engler

15

Development of Power Quality Equipment:

Q-Droop: Grid Support with Reactive Power

0 20 40 60 80 100 120

200

210

220

230

240

250

260

Time (s)

RMS voltage (V)

U1

UDGFACTS

0 20 40 60 80 100 120

0

5

10

15

20

Time (s)

RMS current (A)

0 20 40 60 80 100 120

-3

-2

-1

0

1

2

3

Time (s)

Q (kVAr)

Inverter injects

reactive power

according to the

line line voltage

and supports it

depending on the

line impedance

Realised functions:

• Voltage dependent supply of reactive power (Q droop)

• Dynamic reactive power compensation of dedicated loads

• Dynamic harmonics compensation of dedicated loads

• Flicker reduction

• Local improvement of voltage quality by inductively decoupled subnetworks

236
APEI-Workshop, August 2006, Dr. Ing. A. Engler

16

DeMoTec at ISET

Interconnected Grid Switching Cabinet Medium Voltage Grid

Loads Diesel generator Wind Energy Converter

PV

The design, demonstration and test center (DeMoTEC) at ISET enables 

a variety of relevant tests for DER-components.

237
APEI-Workshop, August 2006, Dr. Ing. A. Engler

17

Interconnecting distribution systems (MV- and LV-Grids)

Line

equivalent

Medium-voltage grid

emulator

10/ 20/ 30 kV

0,4 kV

Diesel-Kraftwerk

Diesel Power Station

10/ 20/ 30 kV

10/ 20/ 30 kV

0,4 kV

0,4 kV

Blockheizkraftwerk BHKW

Combined Heat & Power Sta tion CHP

Photovoltaik

Photovoltaic

Hybridsystem

Hybrid System

Windpark

Wind Park

The Medium voltage grid emulator enables test of equipment for MVdistribution systems.

238
APEI-Workshop, August 2006, Dr. Ing. A. Engler

18

Example for laboratory installation

239
APEI-Workshop, August 2006, Dr. Ing. A. Engler

19 Laboratory demonstration

- Starting diesel genset (tertiary control) -

Screenshot

Of 

SCADA-System

The development of SCADA-Systems and supervisory control 

algorithms enables energy management of grid connected or remote 

hybrid systems.

240
APEI-Workshop, August 2006, Dr. Ing. A. Engler

20

Greek Island Kythnos

Example of small hybrid system installed by ISET and SMA.

241
APEI-Workshop, August 2006, Dr. Ing. A. Engler

21

Greek Island Kythnos

Example of small hybrid system installed by ISET and SMA.

242
APEI-Workshop, August 2006, Dr. Ing. A. Engler

22

Conclusion

- ISETdevelops power electronics for commercial production

- ISET develops advanced control algorithms for grid interfacing

- ISET is able to test equipment in laboratory and field tests

- ISET is a non-profit organisation

ISET e. V

Königstor 59

34119 Kassel

Germany

243
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3. DATES COVERED (From - To)

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5a. CONTRACT NUMBER

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4. TITLE AND SUBTITLE

Advanced Power Electronics Interfaces for Distributed Energy 

Workshop Summary: August 26, 2006, Sacramento, California 

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

NREL/BK-581-40480 

5e. TASK NUMBER

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14. ABSTRACT (Maximum 200 Words)

The Advanced Power Electronics Interfaces for Distributed Energy Workshop, sponsored by the California Energy 

Commission Public Interest Energy Research program and organized by the National Renewable Energy Laboratory, 

was held Aug. 24, 2006, in Sacramento, Calif. The workshop provided a forum for industry stakeholders to share 

their knowledge and experience about technologies, manufacturing approaches, markets, and issues in power 

electronics for a range of distributed energy resources. It focused on the development of advanced power electronic 

interfaces for distributed energy applications and included discussions of modular power electronics, component 

manufacturing, and power electronic applications. 

15. SUBJECT TERMS

power electronics; distributed energy; DER; workshop; advanced power electronics initiative; California Energy 

Commission; CEC; National Renewable Energy Laboratory; NREL 

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