1. Current Contribution from Wind Plant for a System Fault Working Group C17 May 2010 Meeting

3. Details 67 Suzlons S88 2.1MW wind turbine- generator 61 turbine-generators sync. to the system before the fault B ph to gnd fault on 138kV tie line to wind plant occurred at 22:40 11/25/2009

4. Suzlons S88 2.1MW wind turbine- generator A type 2 wound rotor induction generator with variable rotor resistance

5. System One Line

6. Status at Wind Plant before the Fault 61 machines sync to system 14.6MW total output 11.4% of nameplate

7. Mountain Wind Sub 11A relay on line to Muddy Creek

8. Muddy Creek Sub 11A relay on line to Mountain Wind

9. Mountain Wind Sub (Wind Plant) Positive Sequence Current

10. Muddy Creek Sub (System) Positive Sequence Current

11. Generator Impedance

12. Generator Data

13. Using the Asynchronous Generator Values Xs = 0.0536 Xm = 2.6 Xr = 0.0564 X’ = 0.1088 ohms Synchronous data X” = 0.0523 ohms X’ = 0.0941 ohms

14. Generator Step up Transformer Z = 5.75 % @ 2.25MVA

16. Filtered Fault Data

17. Phasor Data

18. Comparison of Results B PhaseI1I2I0I1 + I2 + I0 Measured Time 1 1.1 cycle190839829710921786 Time 2 1.9 cycle185033042010961812 Time 3 3.0 cycle16502303799631535 Time Fault Interrupted 4.1 cycles Fault Study Subtransient178639634610441786 Transient (equivalent synchronous)171334334110291713 Transient (equivalent asynchronous)169232733910251692 Faulted phase voltage on closest generator's terminals0.82 pu

19. Conclusion For relay performance the subtransient reactance using the equivalent synchronous data provides the best fault current values For breaker interrupting currents the transient reactance using the calculated value from the equivalent asynchronous data provides the best fault current values