1. Modelling the NPCC System with 12.5% Wind Penetration
Christopher Matthews
Undergraduate Researcher
Summer REU
July 22, 2015
Knoxville, TN

2. What is a Balancing Authority?
Traditional AGC
Corrects deviations from scheduled system frequency and scheduled tie line exchanges
Each area has a balancing authority
What is a Balancing Authority?

3. Area Control Error 𝐴𝐶𝐸= ∆𝑃 𝑇𝑖𝑒 +𝐵∆𝑓 Damping factor is negligible
𝐵= 1 𝑅 +𝐷
𝑅= ∆𝑓 ∆ 𝑃 𝐺𝑒𝑛
Damping factor is negligible
ACE should cross zero at least once every 10 minutes
MISO Energy ACE Graph
𝑃 𝑇𝑖𝑒 :
Tie-line power 𝑓:
System Frequency 𝐵:
Frequency bias factor 𝑅:
Speed regulation factor 𝐷:
Damping factor
𝑃 𝐺𝑒𝑛 :
Generated power

4. Doubly-Fed Induction Wind Generator
Most common type of wind generator
Asynchronous generation
Requires more control than traditional generators
Added controls adjust power output to maximum

5. Inertial Response Comes from kinetic energy in rotating masses
First few seconds of response
Determines magnitude of frequency excursions
Hidden in variable speed wind turbines

6. User Defined Models using DSATools UDM
Regulating Unit
DFIG

7. Verifying Models Show correct frequency regulation
Tie line flow returns to scheduled with frequency

8. Illustrate effect of losing system inertia

9. AGC Response with Variable Wind

10. Future Work Immediate Response Emulated inertia Droop control
Long Term
Deloading control
Pitch control
Rotational speed control

11. Acknowledgements
This work was supported primarily by the ERC Program of the National Science Foundation and DOE under NSF Award Number EEC
Other US government and industrial sponsors of CURENT research are also gratefully acknowledged.

12. Questions