Impedance Model-Based SSR Analysis for TCSC Compensated Type-3 Wind Energy Delivery Systems

This paper employs impedance model-based frequency domain analysis to detect subsynchronous resonances (SSRs) in Type-3 wind farms with thyristor-controlled series capacitor (TCSC). The contributions of this paper are 1)the derivation of dynamic phasor-based TCSC impedance model and 2)the application of such an impedance model in Type-3 wind energy systems for SSR analysis. Impedance models for TCSC with constant firing angle control and impedance control are derived in this paper. With the derived impedance models, Nyquist stability criterion is applied to compare SSR stability in Type-3 wind farm with TCSC or with fixed capacitor compensation. This paper employs analytical models to demonstrate TCSCs capability in avoiding SSR in Type-3 wind generator interconnection systems. The analytical results obtained through impedance models are validated by detail model-based (with thyristor switch-modeled) time-domain simulation in MATLAB/SimPowerSystems.