Dennis J. Eichenberg

Glenn Research Center, Cleveland, Ohio

A Hybrid Power Management (HPM)

Based Vehicle Architecture

NASA/TM—2011-217021

July 2011
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Dennis J. Eichenberg

Glenn Research Center, Cleveland, Ohio

A Hybrid Power Management (HPM)

Based Vehicle Architecture

NASA/TM—2011-217021

July 2011

National Aeronautics and

Space Administration

Glenn Research Center 

Cleveland, Ohio 44135
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NASA/TM—2011-217021 1

A Hybrid Power Management (HPM)

Based Vehicle Architecture

Dennis J. Eichenberg

National Aeronautics and Space Administration

Glenn Research Center

Cleveland, Ohio 44135

Summary

Society desires vehicles with reduced fuel consumption and reduced emissions. This presents a 

challenge and an opportunity for industry and the government. The NASA John H. Glenn Research 

Center (GRC) has developed a Hybrid Power Management (HPM) based vehicle architecture for space 

and terrestrial vehicles. GRC’s Electrical and Electromagnetics Branch of the Avionics and Electrical 

Systems Division initiated the HPM Program for the GRC Technology Transfer and Partnership Office.

HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration 

for space and terrestrial applications. The appropriate application and control of the various power 

devices significantly improves overall system performance and efficiency.

The basic vehicle architecture consists of a primary power source, and possibly other power sources, 

providing all power to a common energy storage system, which is used to power the drive motors and 

vehicle accessory systems, as well as provide power as an emergency power system. Each component is 

independent, permitting it to be optimized for its intended purpose. This flexible vehicle architecture can 

be applied to all vehicles to considerably improve system efficiency, reliability, safety, security, and 

performance. This unique vehicle architecture has the potential to alleviate global energy concerns, 

improve the environment, stimulate the economy, and enable new missions.

Introduction

NASA has a wealth of experience with alternative energy vehicles. This includes electric vehicles, 

gas turbine powered vehicles, Stirling powered vehicles, and rotary engine powered vehicles.

A battery powered electric vehicle researched by NASA is shown in Figure 1 (Ref. 1). Battery

powered electric vehicles have many advantages including the elimination of the need for fossil fuels, and

no emissions. Battery life has historically been a severe hindrance for electric vehicles. Range is limited 

by batteries. Batteries must be replaced after a few hundred charge/discharge cycles. Battery performance 

is severely affected by cold temperatures. Proper battery charging requires sophisticated electronics.

Battery disposal poses a severe environmental concern.

NASA’s Lunar Roving Vehicle (LRV) shown in Figure 2 was a battery powered electric vehicle that 

used primary, non-rechargeable silver-zinc potassium hydroxide batteries for the Apollo program

(Ref. 2). The LRV was used successfully on Apollo 15, Apollo 16, and Apollo 17.

A gas turbine vehicle researched by NASA is shown in Figure 3 and Figure 4 (Ref. 3). In this vehicle 

a gas turbine replaced the conventional internal combustion engine. Gas turbines have many advantages 

including improved efficiency, significant parts reduction, reduced emissions, high power density, 

operation from a wide variety of fuels, elimination of a water cooling system, reduced maintenance, and 

long life. Drawbacks of gas turbines include poor throttling ability, and poor economy when throttled.
NASA/TM—2011-217021 2

Figure 1.—A battery powered electric vehicle researched by 

NASA in the 1970’s.

Figure 2.—NASA’s Lunar Roving Vehicle was a battery powered 

electric vehicle used successfully on the Moon in the 1970’s.

Figure 3.—A gas turbine vehicle researched by NASA.
NASA/TM—2011-217021 3

Figure 4.—A gas turbine engine replaced the internal combustion engine in 

the gas turbine vehicle.

Figure 5.—A Stirling powered vehicle researched by NASA 

in the 1970’s.

Stirling powered vehicles, as shown in Figure 5, were studied by NASA in the 1970’s (Ref. 4). A 

Stirling engine, as shown in Figure 6, replaced the internal combustion engine. Stirling engines provide 

higher efficiency, lower emissions, operation from a wide variety of fuels, have reduced maintenance, and 

have long life. Stirling powered vehicles require a warm up time and do not throttle very well.

Rotary, or Wankel, engines, as shown in Figure 7, were studied for vehicle use by NASA in the 

1970’s (Ref. 5). Advantages of rotary engines include high power density and smooth operation. 

Disadvantages include complex sealing issues and poor fuel economy.
NASA/TM—2011-217021 4

Figure 6.—A Stirling engine researched by NASA in 

the 1970’s.

Figure 7.—A rotary engine researched by NASA in the 1970’s.
NASA/TM—2011-217021 5

In the 1990’s NASA GRC developed a hybrid electric transit bus (HETB), as shown in Figure 8

(Ref. 6). This is a 37,000-lb gross weight, 40-ft transit bus which incorporates HPM. The vehicle has

many unique features. A natural gas powered internal combustion engine drives an electric generator to 

charge a bank of ultracapacitors, shown in Figure 9, which delivers power to a variable speed electric 

motor that drives the rear axle, as well as to the accessories. Ultracapacitors are ideal for this application 

in that they can repeatedly handle the extremely high charge and discharge currents associated with a 

heavy hybrid vehicle. The bus uses regenerative braking to improve fuel efficiency. This technology 

recovers much of the kinetic energy of the vehicle during deceleration. This replenishes the energy 

storage system each braking cycle and extends the life of the mechanical brakes. The HETB met the 

Department of Transportation (DOT) White Book acceleration specifications. Fuel economy for a 

modified Commercial Business District Cycle was 21 percent greater with regenerative braking than 

without. Ultracapacitors proved to provide significantly better braking performance than batteries. The 

hybrid configuration provides extended range, improved fuel economy, lower emissions, and higher 

performance. Disadvantages include greater complexity.

Figure 8.—The NASA Hybrid Electric Transit Bus (HETB).

Figure 9.—The bank of ultracapacitors installed in the NASA 

Hybrid Electric Transit Bus (HETB).
NASA/TM—2011-217021 6

In the 2000’s NASA GRC developed an HPM based fuel cell powered utility vehicle as shown in 

Figure 10. This is an electric vehicle powered by a proton exchange membrane (PEM) fuel cell, as shown 

in Figure 11. A bank of ultracapacitors, shown in Figure 12, provides energy storage for the vehicle. The

utility vehicle was successfully utilized as an HPM test bed (Refs. 7, 8, and 9). A baseline test was 

completed with the utility vehicle in its standard commercial configuration with lead acid batteries. It was 

then tested with power provided only by ultracapacitors, and then tested with fuel cells installed. The fuel 

cell powered vehicle utilizes two PEM fuel cells, with ultracapacitor energy storage, and metal hydride 

hydrogen storage. The ultracapacitors act as a buffer to provide the transient power required for the 

vehicle without damaging the delicate fuel cell membrane. The metal hydride hydrogen storage system 

stores the hydrogen in a safe controlled manner.

Figure 10.—A fuel cell powered utility vehicle equipped with 

ultracapacitors.

Figure 11.—A proton exchange membrane (PEM) fuel cell powers 

the utility vehicle.
NASA/TM—2011-217021 7

Figure 12.—A bank of series connected ultracapacitors for the utility vehicle.

Photovoltaic Power Systems

In addition to vehicles, HPM has been successfully applied to photovoltaic power systems (Refs. 10, 

11, and 12). Ultracapacitors complement photovoltaic arrays extremely well. The long cycle life and

excellent low temperature characteristics of the ultracapacitors complement the characteristics of the 

photovoltaic arrays, resulting in a higher performance power system.

A stand alone photovoltaic system was developed at NASA GRC, as shown in Figure 13 that 

incorporates photovoltaic panels, ultracapacitors and a sine wave inverter. The photovoltaic panels are 

mounted on a passive tracking system to improve system efficiency. The ultracapacitors provide short 

term energy storage. Tests results indicated a significant performance improvement with the addition of 

ultracapacitors to the system.

A grid-tied photovoltaic system was also developed at NASA GRC, as shown in Figure 14. The gridtied system has been an efficient, reliable source of ac power to the GRC utility system.

The HPM based vehicle architecture discussed here is developed from the experience derived from 

the previous vehicle and power systems.

Objectives

The objective of the HPM based vehicle architecture is to improve vehicle system efficiency, 

reliability, safety, security, and performance. The flexibility of the vehicle architecture provides 

opportunities for a very wide range of applications, including space and terrestrial missions. 

This effort makes a significant contribution to addressing the national and state interests to reduce 

fuel consumption and reduce emissions. In addition, this is an excellent opportunity to capitalize on, and 

transfer technology from the aerospace and military industries to a commercial venture.
NASA/TM—2011-217021 8

Figure 13.—An ultracapacitor backed photovoltaic power 

system at GRC.

Figure 14.—A grid-tied photovoltaic system installed at GRC.
NASA/TM—2011-217021 9 

Discussion

Hybrid Power Management

Peak power requirements of most vehicles are many multiples of their steady state value. This 

requires a power source large enough to handle the peak power requirement. An excessively large power 

source reduces system efficiency. The severe nature of transient loads reduces vehicle life and reliability. 

HPM can significantly improve vehicle efficiency, life, reliability, and performance (Ref. 13). 

The unique aspects of HPM are indicated clearly in the HPM system diagram shown in Figure 15. 

The central feature is the energy storage system, in which an ultracapacitor is an ideal candidate, due to its 

long cycle life, high reliability, high efficiency, high power density, and excellent low temperature 

performance. All generated power is sent to the energy storage system, and all loads derive their power 

from the energy storage system. The system readily accommodates multiple power sources and multiple 

loads. A hybrid power management controller maintains optimal control over each of the components of 

the entire system. 

Greater understanding of HPM can be achieved through a comparison to the human physiology as 

indicated in the HPM human analogy diagram shown in Figure 16. The central feature is the energy 

storage system, which is the stomach in the human case. All generated power is sent to the energy storage 

system, and all loads (muscles) derive their power from the energy storage system. There can be multiple 

power sources, each optimized for a particular operating condition. There can be multiple loads as 

required, each connected to the energy storage system. The brain serves as the hybrid power management 

controller to maintain optimal control over each of the components of the entire system.

Figure 15.—A system diagram of Hybrid Power Management (HPM).

ENERGY STORAGE SYSTEM

(such as ultracapacitors)

HYBRID POWER 

MANAGEMENT CONTROLLER

PRIMARY POWER

SOURCE

(such as a 

generator)

SECONDARY 

POWER SOURCE

(such as solar)

OTHER POWER 

SOURCES

(such as 

thermal)

PRIMARY LOAD

(such as a drive 

motor)

SECONDARY 

LOAD

(such as an 

accessory)

OTHER LOADS

(such as other 

accessories)

HYBRID POWER MANAGEMENT (HPM)

System Diagram

energy

control
NASA/TM—2011-217021 10

Figure 16.—A human analogy of Hybrid Power Management (HPM).

General HPM Vehicle Architecture

The general HPM vehicle architecture discussed here consists of electric motors for traction drive and 

regenerative braking, powered by multiple primary power sources, with an energy storage system, and all 

electric accessories, controlled by an HPM power management controller. This general architecture is 

shown in Figure 17. 

The evolution of power electronics technology has offered the possibility of revolutionary drive trains 

for vehicles. Electric motors using efficient solid state power devices offer infinitely variable power and 

speed control. Several of the motors currently being offered by industry have very high power densities 

and can be controlled to also act as generators. When coupled with onboard energy storage systems, such 

as batteries, flywheels, or ultracapacitors, this drive train offers several advantages including: 

• Improved fuel economy

• Reduced emissions

• Lower noise levels

• Elimination of multiple-gear transmissions

• Elimination of fluid coupling losses

• Near constant speed and load to the primary power source

• Recovery of energy during braking 

• Reduced drive train and brake maintenance

• Flexible vehicle configuration for improved vehicle design

HYBRID POWER MANAGEMENT (HPM)

A Human Analogy

Power Source

Hybrid Power Management

Controller

Load

Load

Load

Energy Storage System

energy

control
NASA/TM—2011-217021 11

Figure 17.—General HPM vehicle architecture.

Electrical power trains with energy storage uncouple the short-term power requirements of the vehicle 

from the load seen by the primary power source. Thus the primary power source in such a power train can 

operate at its highest efficiency design point. In addition, the size of the primary power source can be 

reduced significantly in some vehicles and drive cycles to the long-term average value of power. Energy 

storage provides the short term power supplement needed during acceleration and for going up a grade. 

This reduced power source size, higher efficiency, and constant speed yields significantly improved 

emissions, fuel economy, and life for the primary power source.

The energy storage system is necessary to provide a smooth power requirement to the primary power 

source and as a place to absorb the regenerative braking energy. Regenerative braking significantly 

improves vehicle efficiency, and braking performance, providing consistent braking over time.

Regenerative braking can be used to perform complete stops under most driving conditions, which 

significantly extends mechanical brake life, thus improving safety and reliability, and reducing 

maintenance costs.

The individually powered electric accessories (such as air conditioning, power steering, and power 

brakes) eliminate the parasitic loads of the accessories as they are only operated when required. This 

improves economy and life. This configuration also allows the accessories to be located in the optimum 

location in the vehicle, rather than a central location.

The HPM vehicle architecture also provides an auxiliary power system for facility power. This is 

used as an emergency backup power system in the event of a utility power system failure. It can also be 

used to supplement the utility power system.

The energy storage system allows the vehicle to readily accommodate multiple power sources.

Multiple power sources can improve vehicle efficiency, and allows accessories, such as the air 

conditioning, to be operated when the primary power source is not operating. The additional power 

sources can also be used for the auxiliary power system.

The HPM power management controller provides control over the entire vehicle power system to 

maintain optimum efficiency and safety.

Gas Turbine Based HPM Vehicle Architecture

Based upon presently available technology, the gas turbine based HPM vehicle architecture being 

discussed consists of four or more electric wheel motors for traction drive and regenerative braking, 

powered by one or more gas turbine generators, along with a photovoltaic power system, and all electric 

accessories, controlled by a hybrid power management controller. This configuration is shown in Figure 18.
NASA/TM—2011-217021 12

Figure 18.—Gas turbine based HPM vehicle architecture.

This flexible vehicle configuration permits the vehicle layout to be determined by its mission, rather 

than by its components. The vehicle can be designed for maximum efficiency for its intended application. 

Parameters such as load carrying capability, maximum acceleration, maximum speed, or maximum 

traction can be considered.

Traction Motors

Electric wheel motors are optimal for the HPM vehicle architecture. Electric motors produce 

maximum torque at zero speed, which is ideally suited for vehicle operations. Electric motors provide 

consistent performance over their life, unlike internal combustion engines whose performance degrades.

The motors provide infinitely variable speed control. This eliminates the need for a transmission, which 

saves weight and cost, and improves efficiency and reliability. Electric wheel motors provide optimal 

drive and braking characteristics. Any quantities of drive wheels are possible with this technology. This 

configuration facilitates traction control, anti-skid braking, and yaw control through the dynamic control 

of the motors. Multiple wheel motors permit the use of tires with decreased aerodynamic drag and rolling

resistance. Regenerative braking significantly improves vehicle efficiency, and braking performance, 

providing consistent braking over time. Regenerative braking can be used to perform complete stops 

under most driving conditions, which significantly extends mechanical brake life, thus improving safety 

and reliability, and reducing maintenance costs. Regenerative braking reduces the emission of brake 

material and heat produced by mechanical brakes. It also significantly reduces the environmental concern 

from brake disposal. Mechanical brakes must be provided for braking at very low speeds, and as a backup 

for the regenerative braking in the event of a motor control failure.

Ultracapacitor Energy Storage System

The central feature of HPM is the energy storage system. All generated power is sent to the energy 

storage system, and all loads derive their power from the energy storage system. An HPM energy storage 

system must be extremely reliable, have an extensive life, and must have very high efficiency, since all 

generated power is sent to the energy storage system, and all loads derive their power from the energy 

storage system. The ultracapacitor is an ideal candidate for an HPM energy storage system. A capacitor is 

an electrical energy storage device consisting of two or more conducting electrodes separated from one 

another by an insulating dielectric. An ultracapacitor is an electrochemical energy storage device, which 

has extremely high volumetric capacitance energy due to high surface area electrodes, and very small 

electrode separation. Commercially available ultracapacitors provide a reliable, long life, maintenance 

free, energy storage system, and have many advantages over energy storage systems such as batteries.
NASA/TM—2011-217021 13

• Batteries can only be charged and discharged hundreds of times, and then must be replaced.

Ultracapacitors can be charged and discharged over 1 million times. The long cycle life of 

ultracapacitors greatly improves system reliability, and reduces life-of-system costs.

• Long ultracapacitor life significantly reduces environmental impact, as ultracapacitors will 

probably never need to be replaced and disposed of in most applications. 

• The environmentally safe components of ultracapacitors greatly reduce disposal concerns.

• High ultracapacitor power density provides high power during acceleration, and the ability to 

absorb high power during regenerative braking. Ultracapacitors are extremely efficient in 

capturing regenerative braking energy.

• Ultracapacitors are extremely rugged, reliable, and maintenance free.

• Ultracapacitors have excellent low temperature characteristics.

• Ultracapacitors provide consistent performance over time.

• Ultracapacitors promote safety, as they can easily be discharged, and left indefinitely in a safe 

discharged state.

Gas Turbine Generator

Electric utility power was originally provided by reciprocating engines. Turbine generators were then 

implemented which provided greater efficiency, improved reliability, and longer life, and became the 

standard power source. Gas turbine generators are commercially available and are an ideal power source 

for the HPM vehicle architecture. In spite of the many advantages of the gas turbine over the internal 

combustion engine, it does not make a good power source to drive the vehicle directly because it does not 

throttle very well, requiring optimum speed operation to achieve good efficiency. Turbines also have 

throttle lag. These problems are resolved with a hybrid configuration in which the turbine is configured as 

an electric generator to power the electric drive motors. The turbine can be operated at the optimum speed 

in a hybrid configuration. The gas turbine generator offers many advantages over reciprocating engines.

• Higher efficiency

• Higher power density

• Reduced emissions

• Operational on alternative fuels

• Smooth and quiet operation

• High reliability

• Lower maintenance

• Longer life

• Parts count reduced by 80 percent

• Lower manufacturing costs

• Solitary start-up spark plug eliminating a distributor

• Regular oil changes not required as no combustion contaminants enter oil

• No water cooling system and antifreeze required

• Easy low-temperature starting

• No warm-up required

• Instant heat available in the winter

Multiple gas turbines can be used independently as HPM vehicle power sources. The architecture 

permits one turbine to be used as a power source, and other turbines to be turned on as necessary to meet the 

specific vehicle power requirement, and then shutdown when not required to limit fuel use and emissions.

As other technologies, such as fuel cells, mature, they may become credible alternatives for the HPM 

vehicle architecture power source in the future.
NASA/TM—2011-217021 14

Photovoltaic Power System

Modern photovoltaic (PV) panels are readily available, reliable, efficient, and economical with a life 

expectancy of at least 25 years, and make an ideal secondary power source for the HPM vehicle 

architecture. The PV panels are semiconductor panels that convert energy from sunlight to DC electrical 

power. The panels are unbreakable and maintenance free. PV is entirely pollution free during use. PV 

system production end wastes and emissions are manageable utilizing existing pollution controls. End-ofuse recycling technologies are under development to minimize negative environmental effects. PV 

systems can operate with minimal operator intervention or maintenance after initial setup.

Control System

The hybrid power management controller provides sequencing for system/subsystem startup and 

shutdown as well as control of the state of discharge of the energy storage system. The state of the energy 

storage must be optimized to allow for full recovery of energy during braking while also providing adequate 

vehicle performance. The vehicle must respond to operator accelerator and brake controls as similarly as 

possible to the response of a conventional vehicle. The choice of the energy storage system and its

associated electrical characteristics strongly influences the design of the vehicle control strategy. The 

ultracapacitor system has several characteristics that are significantly different from those of conventional 

chemical storage batteries. First the state of charge of capacitors can be determined very precisely from the 

measured capacitor voltage. This is a significant advantage over chemical batteries in which the relationship 

between voltage and state of charge is non-linear. Chemical batteries also exhibit hysteresis of their voltage, 

current, state of charge characteristics. Battery energy storage systems require a much more sophisticated

state of charge control system. A second difference between batteries and capacitors is that batteries must be 

current (and/or cell voltage), limited especially when being charged. This is even more critical as the battery 

achieves full charge. Near full charge lead acid and many other chemical batteries are unable to accept high 

currents without damage. To prevent loss of battery life, additional hardware and software is needed which 

again adds complexity of the charge control system. Ultracapacitors, on the other hand, have very high 

current capabilities and efficiency, approach their voltage limit more slowly, and do not experience damage 

while accepting current below full charge. Overall, the use of ultracapacitor energy storage reduces the 

complexity of the power operation of the vehicle which uses ultracapacitor voltage as feedback to control 

the power set point, updated continuously, of the engine generator set.

Auxiliary Power System

Society is concerned with the security of the electric utility system. The HPM architecture allows the 

vehicle to serve as a mobile power generator. A gas turbine is an excellent long life power source, and 

lends itself to use for this application. The generator can be used to power a home, and multiple vehicles 

can be used to power hospitals and other critical institutions. This enhances safety and security. The 

photovoltaic power system is an ideal source for the auxiliary power system during daylight hours. The 

photovoltaic power system can be used to provide emergency backup power, and can also be used to 

supplement the utility power system, reducing the burden on the utility. Parked school buses at a school 

could provide much, and perhaps all, of the power required by the school during the day when the highest 

level of power is required, significantly lowering fuel use, emissions, and energy costs.

Modern electronics is the enabling technology behind grid-tied power systems, making them safe, 

reliable, efficient, and economical with a life expectancy of at least 25 years. A grid-tied power system is 

connected directly to the utility distribution grid. Facility power can be obtained from the utility system as 

normal. The auxiliary power system is synchronized with the utility system. The auxiliary power system 

provides power for the facility, and excess power is provided to the utility. For safety, an automatic 

transfer switch permits the vehicle to provide power to the facility when utility power is unavailable, and 

automatically switch back to utility power when it does become available.
NASA/TM—2011-217021 15

Figure 19.—HPM is being investigated for numerous space exploration applications.

Grid-tied power systems provide many benefits. Operating costs of a PV power system are low 

compared to conventional power technologies. PV can displace the highest cost electricity during times of 

peak demand in most climatic regions, and thus reduce grid loading. Net metering is often used, in which 

independent power producers, such as PV power systems, are connected to the utility grid via the 

customers’ main service panel and meter. When the PV power system is generating more power than 

required at that location, the excess power is provided to the utility grid. The customer pays the net of the 

power purchased when the on-site power demand is greater than the on-site power production and the 

excess power that is returned to the utility grid.

Rovers

The HPM technology developed for the terrestrial applications described is now being applied to the 

next generation of lunar rovers and other space exploration vehicles (Ref. 14), as depicted in Figure 19.

HPM is ideal for space applications where long life, high efficiency, extreme reliability, and excellent low 

temperature performance is critical. Many of the HPM components, such as fuel cells, photovoltaic panels, 

and ultracapacitors, are being integrated into optimal configurations for space exploration vehicles.

Concluding Remarks

The Hybrid Power Management (HPM) based vehicle architecture provides a practical solution to 

reducing fuel consumption and emissions from vehicles, while providing the capability to operate from 

alternative fuels, and fulfilling a need for an effective backup facility power system.

The key element of HPM is the energy storage system. All generated power is sent to the energy 

storage system, and all loads derive their power from the energy storage system. This technique can 

significantly reduce the power requirement of the primary power source, while increasing the vehicle
NASA/TM—2011-217021 16

reliability. Ultracapacitors are ideal for HPM based energy storage systems due to their exceptionally long 

cycle life, high reliability, high efficiency, high power density, and excellent low temperature 

performance. Multiple power sources and multiple loads are easily incorporated into an HPM based 

vehicle. A hybrid power management controller maintains optimal control over each of the components 

of the entire vehicle. This flexible operating system can be applied to all vehicles to considerably improve 

vehicle efficiency, reliability, safety, security, and performance.

The HPM based vehicle architecture has the potential to provide significant improvements in space 

and terrestrial based vehicles.

References

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3. Helms, H.E., Kaufeld, J., Kordes, R., “Advanced Gas Turbine (AGT) Power-Train System 

Development,” NASA-CR-165504, December 1981.

4. Nightingale, N., Ernst, W., Richey, A., Simetkosky, M., “Automotive Stirling Engine Development 

Program,” NASA-CR-167907, October 1982.

5. Willis, E.A., and McFadden, J.J., “Rotary Engine Technology,” Aeropropulsion 1991.

6. Brown, J.C., Eichenberg, D.J., and Thompson, W.K., “Baseline Testing of the Hybrid Electric Transit 

Bus,” NASA Technical Memorandum 208890, January 1999.

7. Eichenberg, D.J., “Baseline Testing of the Club Car Carryall With Asymmetric Ultracapacitors,”

NASA Technical Memorandum 212705, November 2003.

8. Eichenberg, D.J., “The Fuel Cell Powered Club Car Carryall,” NASA/TM—2005-214024, December 

2005.

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Vehicle,” NASA/TM—2006-214016.

10. Eichenberg, D.J., Kolacz, J.S., and Tavernelli, P.F., “Baseline Testing of the Ultracapacitor Enhanced 

Photovoltaic Power Station,” NASA Technical Memorandum 211316, November 2001.

11. Eichenberg, D.J., “Development and Testing of a Prototype Grid-Tied Photovoltaic Power System,”

NASA/TM—2009-216062, 2009.

12. Eichenberg, D.J., “Development and Testing of the GRC Visitor’s Center Grid-Tied Photovoltaic 

Power System,” NASA/TM—2009-215847, 2009.

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14. Zakrajsek, J.J., McKissock, D.B., Woytach, J.M., Zakrajsek, J.F., Oswald, F.B., McEntire, K.J., Hill, 

G.M., Abel, P, Eichenberg, D.J., and Goodnight, T.W., “Exploration Rover Concepts and 

Development Challenges,” NASA Technical Memorandum 213555, March 2005.
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PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 

1. REPORT DATE (DD-MM-YYYY)

01-07-2011 

2. REPORT TYPE

Technical Memorandum 

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

A Hybrid Power Management (HPM) Based Vehicle Architecture 

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

Eichenberg, Dennis, J. 

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

WBS 069746.02.03.0485.02 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

John H. Glenn Research Center at Lewis Field 

Cleveland, Ohio 44135-3191 

8. PERFORMING ORGANIZATION

 REPORT NUMBER

E-17686 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration 

Washington, DC 20546-0001 

10. SPONSORING/MONITOR'S

 ACRONYM(S)

NASA 

11. SPONSORING/MONITORING

 REPORT NUMBER

NASA/TM-2011-217021 

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified-Unlimited 

Subject Category: 44 

Available electronically at http://www.sti.nasa.gov 

This publication is available from the NASA Center for AeroSpace Information, 443-757-5802

13. SUPPLEMENTARY NOTES

14. ABSTRACT

Society desires vehicles with reduced fuel consumption and reduced emissions. This presents a challenge and an opportunity for industry 

and the government. The NASA John H. Glenn Research Center (GRC) has developed a Hybrid Power Management (HPM) based vehicle 

architecture for space and terrestrial vehicles. GRC’s Electrical and Electromagnetics Branch of the Avionics and Electrical Systems 

Division initiated the HPM Program for the GRC Technology Transfer and Partnership Office. HPM is the innovative integration of diverse, 

state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of 

the various power devices significantly improves overall system performance and efficiency. The basic vehicle architecture consists of a 

primary power source, and possibly other power sources, providing all power to a common energy storage system, which is used to power 

the drive motors and vehicle accessory systems, as well as provide power as an emergency power system. Each component is independent, 

permitting it to be optimized for its intended purpose. This flexible vehicle architecture can be applied to all vehicles to considerably 

improve system efficiency, reliability, safety, security, and performance. This unique vehicle architecture has the potential to alleviate global 

energy concerns, improve the environment, stimulate the economy, and enable new missions.

15. SUBJECT TERMS

Automobiles; Electric automobiles; Energy conversion; Electric power 

16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

 ABSTRACT

UU 

18. NUMBER

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 PAGES

22 

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email:help@sti.nasa.gov) 

a. REPORT

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b. ABSTRACT

U 

c. THIS 

PAGE

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19b. TELEPHONE NUMBER (include area code)

443-757-5802 

Standard Form 298 (Rev. 8-98)

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