Variable-speed Wind Generation Control for Frequency Regulation in the Eastern Interconnection (EI) Yong Liu, Joe Gracia, Tom King, Yilu Liu April. 17 th , 2014 1
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
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• 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
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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
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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
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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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