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Active Power Control from Wind Power

Erik Ela, Daniel Brooks

4/15/2011

UWIG Spring Meeting

Kansas City, Missouri

Erik.Ela@nrel.gov

NREL/PR-5500-51488

PIX 16562
Creating Options

Creating the Options: Integrating wind, operating the 

power system.

Selecting the Options: Optimize the economics, 

enhance the reliability.

National Renewable Energy Laboratory Innovation for Our Energy Future
Team

NREL

Erik Ela

Vahan Gevorgian

Paul Fleming

Ed Muljadi

Colorado School of Mines

Kathryn Johnson

Yunho Jeong

National Renewable Energy Laboratory Innovation for Our Energy Future

EPRI

Daniel Brooks

Pouyan Pourbeik

Aidan Tuohy
Active Power Operating Reserves

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Operating 

Reserve

Regulating 

Reserve

Contingency 

Reserve

Following 

Reserve

primary

Ramping 

Reserve

Non-event Event

Correct the current ACE

Manual

Part of optimal 

dispatch

Instantaneous Non-Instantaneous

secondary tertiary secondary tertiary

FrequencyStabilize 

zeronominal and/or ACE to Return Frequency to 

and secondaryReplace primary 

zeronominal and/or ACE to Return Frequency to 

Replace secondary

Automatic

Within optimal 

dispatch

ACECorrect the anticipated 
Active Power Operating Reserves

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Operating 

Reserve

Regulating 

Reserve

Contingency 

Reserve

Following 

Reserve

primary

Ramping 

Reserve

Non-event Event

Correct the current ACE

Manual

Part of optimal 

dispatch

Instantaneous Non-Instantaneous

secondary tertiary secondary tertiary

FrequencyStabilize 

zeronominal and/or ACE to Return Frequency to 

and secondaryReplace primary 

zeronominal and/or ACE to Return Frequency to 

Replace secondary

Automatic

Within optimal 

dispatch

ACECorrect the anticipated 
Active Power Control

• Inertial Response

• Primary Frequency Response (Governor Response)

• Secondary Response (AGC, ACE Regulation, Load 

Frequency Control)

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National Renewable Energy Laboratory Innovation for Our Energy Future

Making the Case

 Current decline of the North American Eastern Interconnection 

frequency response of about 60-70 MW/0.1 Hz per year 

 Ingleson and Allan 2010, Ingleson and Ellis 2004, etc.

 2011 FERC/LBNL study on Frequency Response Metrics to 

assess requirements for reliable integration of VG 

 recommends “expanded use of frequency control capabilities that could be 

provided by variable renewable generation technologies (primary frequency 

control, etc.)”

 Kirby et al “Providing minute to minute regulation from wind 

plants”

 “The analysis has shown that there is a potential for wind plants to aid 

power system reliability and increase their own profits by providing 

regulation.”

 Wind power integration studies (e.g. EWITS, WWSIS, etc.) have 

recommended use of wind power providing secondary and 

tertiary reserve power during min load periods
Differences in Perspective

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Operators

Wind 

Owner/Operator

Manufacturer

Sure I desire it, 

but why would I 

ask them to 

provide the 

capability if they 

cannot provide it?

Why would I provide 

that capability if I can’t 

make money from it 

and lose money in the 

energy market?

Sure I can build 

this, but why 

market this 

capability if nobody 

desires it?

Regulator

Why create a 

market for that 

capability if it 

currently is given 

for free?

Research and 

Demonstration
Active Power Control Project

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• NREL and EPRI joint project, to test at NWTC facilities

• Economic and power system analysis and simulations

• Computer simulations of control capabilities

• CART machine field test

• Utility scale wind turbine test and demonstration

• Parameter adjustments (dead bands, ramp rates, droop 

characteristic, etc.)

• Different wind speeds, upward and downward, high varying wind

• All three responses together

• Publish results and demonstrate to regulators, operators, wind 

owner/operators, and manufacturers
Active Power Control from Wind Power Workshop

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www.nrel.gov/wind/systemsintegration/active_power_control_workshop.html
Key Takeaways

• Do we need a new vernacular? Does the existing 

terminology still work?

• Have we determined what the right goal is yet?

• Frequency response vs. nadir response, nadir vs. settling 

frequency, CPS2 vs. BAAL? Will the need change based on 

what policies are driving requirements?

• UFLS setting???

• Of the response categories, which will need wind to 

assist in first, which will cost wind the most to 

provide, and which will overall be the most important 

product

National Renewable Energy Laboratory Innovation for Our Energy Future
Key Takeaways

• Markets vs. policy???

• How will requirements change the steady state needs

• Can primary, inertial response, influence unit commitment 

decisions?

• How can we turn all of our knobs to give the most 

desired response without necessarily copying the 

physical responses of conventional generation?

• Have we tried everything to see what can go wrong

• “Turn over the rocks and look for snakes”

• Who else needs to see these test results? What test 

results does who need to see?

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Project Tasks

National Renewable Energy Laboratory Innovation for Our Energy Future

Task1: Steady 

State and 

economic 

analysis

Task2: 

Transient 

Analysis

Task3: 

Turbine 

Controls 

Simulation

Task4: 

Turbine Field 

Test

Farm Field 

Test

Task5: 

Dissemination 

of results to 

key 

stakeholders
Steady State and Economic Analysis

• Unit commitment and dispatch with wind providing 

services

• AGC regulation

• Primary frequency response

• Inertia

• Higher resolution steady

state modeling.

• Can wind follow AGC?

• Finding the marginal 

cost (dual) of various 

control constraints

• What is the priority?

• What is the business case?

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$1,305,000

$1,310,000

$1,315,000

$1,320,000

$1,325,000

$1,330,000

$1,335,000

$1,340,000

$1,345,000

Combined no wind Separate no wind Combined with wind Separate with wind
Transient Analysis

• Investigate wind power contribution into power 

system overall frequency response

• Test different wind turbine types (3 and 4) 

• Test different inertial algorithms

• Test different droop characteristics, deadbands, 

limits, etc.

• Above tasks can be done for various power 

system configurations

• Different generation mixes (hydro, steam, gas) 

• Different droop characteristics for conventional 

generation 

• Cases when conventional generators do not 

provide droop 

• What is the needed response?

• How does the wind response assist?

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Modified Droop Characteristics

General Droop Characteristic
Advanced Controls Research at NWTC

16

• What does the response look like?

• How does it compare to current providers?

• How does it affect the machine life, etc.?

PIX 18292
Schedule

• September-December 2010: Project initiation, 

cooperative research and development agreement.

• January 2011: Active Power Control from Wind 

Power Workshop in Boulder, CO.

• February-March 2011: Project technical kickoff, 

scope breakdown.

• Late 2011: Interim project report.

• October 2010 – April 2011: Next wind season field 

tests.

• Late 2012: Final project report, demonstrations.

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Industry Guidance

Workshop participants and other interested partners will 

be kept aware of project as it moves forward.

Erik.Ela@nrel.gov

dbrooks@epri.com

www.nrel.gov/wind/systemsintegration/projects_modelin

g_interconnection.html

National Renewable Energy Laboratory Innovation for Our Energy Future
Questions??

National Renewable Energy Laboratory Innovation for Our Energy Future