A Method to Aggregate Turbine and Network Impedances for Wind Farm System Resonance Analysis

摘要

New sequence impedance models that account for additional harmonics caused by nonlinearity of PLL and dc bus voltage control have been developed for grid connected converters to improve their accuracy in predicting system resonance. This paper extends the method to wind farms with large number of turbines and develops aggregated farm sequence impedance models to account for the nonlinearity in individual turbine models as well as coupling among different turbines. The developed models are validated by detailed circuit simulation and demonstrated by system case studies.