Variable-speed Wind Generation Control for Frequency Regulation in the Eastern

Interconnection (EI)

Yong Liu, Joe Gracia, Tom King, Yilu Liu

April. 17th, 2014

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New Challenges by Wind Developments

2

• Not Contribute to Frequency Regulation

• “Hidden” inertia

• Frequency support control not available now

• Impact System Dynamics Performance

• Impact existing electromechanical modes

• Introduce new modes

Wind Power Capacity of US since 2000

Wind Resources in US

Capability of Power Electronics Converter

• Transient Condition: if with additional controller

• Frequency Regulation

• Inter-area Oscillation Damping

DFIG PMSG

3

Simulation Setup

• EI system model

• TVA 16,000-bus dynamic model

• 590 GWs / 3000+ generators

• Wind generation model

• Based on PSS/E GE WT3 DFIG wind model

• User-defined electrical control model that

includes additional controllers

• Assume wind is 5% of total EI capacity

4

Wind Generation Location Map

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Frequency Regulation • Wind Inertia Control:

• Utilization of kinetic energy

• Does not change the stable operating point

• GE commercial product

• Wind Governor Control:

• Wind turbine works in over-speeding zone for reserve

• Decrease rotational speed to release reserve in seconds

• Wind AGC Control:

• Also needs reserve

• May be more effective than conventional generation AGC

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Case Study-Generation trip

0 5 10 15 20 25 30

-2

-1

0x 10

-4 EI Frequency Response

Time (s)

Fre

quency D

evia

tion (

pu)

Base Case

with Wind Inertia Control

with Wind Governor Control

with both Wind Inertia and Wind Governor Control

with Wind Inertia and Wind Governor Control and AGC at 10s

0 5 10 15 20 25 300.995

1

1.005

1.01

1.015

1.02

1.025

1.03

1.035

Active Power Output of One Wind Farm

Time (s)

Active P

ow

er(

100 M

W)

Base Case

with W ind Inertia Control

with W ind Governor Control

with both W ind Inertia and W ind Governor Control

with W ind Inertia and W ind Governor Control and AGC at 10s

7

Case Study-Generation trip

0 5 10 15 20 25 30-12

-10

-8

-6

-4

-2

0

x 10-3 Turbine Speed Deviation

Time (s)

Turb

ine S

peed D

evia

tion(p

u)

Base Case

with W ind Inertia Control

with W ind Governor Control

with both W ind Inertia and W ind Governor Control

with W ind Inertia and W ind Governor Control and AGC at 10s

0 5 10 15 20 25 300.995

1

1.005

1.01

1.015

1.02

1.025

1.03

1.035

Active Power Output of One Wind Farm

Time (s)

Active P

ow

er(

100 M

W)

Base Case

with W ind Inertia Control

with W ind Governor Control

with both W ind Inertia and W ind Governor Control

with W ind Inertia and W ind Governor Control and AGC at 10s

8

Case Study-Generation trip

0 5 10 15 20 25 30

-0.03

-0.025

-0.02

-0.015

-0.01

-0.005

0

0.005

0.01

0.015

0.02

Reactive Power Output of One Wind Farm

Time (s)

Reactive P

ow

er(

100 M

Var)

Base Case

with W ind Inertia Control

with W ind Governor Control

with both W ind Inertia and W ind Governor Control

with W ind Inertia and W ind Governor Control and AGC at 10s

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Case Study-Load Shedding

0 5 10 15 20 25 300

1

2

3

4

x 10-4 EI Frequency Response

Time (s)

Fre

quency D

evia

tion (

pu)

Base Case

with W ind Inertia Control

with W ind Governor Control

with both W ind Inertia and W ind Governor Control

with W ind Inertia and W ind Governor Control and AGC at 10s

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Summary and Conclusion

• Wind Inertia Control helps reduce the frequency deviation nadir.

• Wind Governor Control mainly contributes to improve the settling frequency.

• Wind AGC Control has the potential to bring the settling frequency back to 60Hz.

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Acknowledgements • This work was primarily funded by the Oak Ridge National

Laboratory.

• This work made use of Engineering Research Center Shared

Facilities supported by the Engineering Research Center Program of

the National Science Foundation and DOE under NSF Award

Number EEC-1041877 and the CURENT Industry Partnership

Program.

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