Coordinated FCS-MPC and Auxiliary Damping Control for Enhanced SSR Mitigation in Series-Compensated DFIG Wind Farms

This study proposes a comprehensive and novel coordinated control framework to effectively mitigate sub-synchronous resonance (SSR) in a doubly-fed induction generator based on wind turbines connected to series-compensated transmission lines. The proposed approach integrates finite control model predictive control in the rotor-side converter to achieve fast and accurate current tracking, while an SSR damping controller is embedded in the grid-side converter (GSC). Through coordinated operation, the GSC injects an auxiliary damping signal into the q-axis current reference to suppress sub-synchronous oscillations while maintaining DC-link voltage stability. Time-domain simulations conducted under diverse operating conditions demonstrate the robustness and superior performance of the proposed scheme. In particular, the total harmonic distortion is reduced from over 2.3% to below 2.0%, and the maximum electromagnetic torque oscillation is significantly suppressed from over 1.0 pu to approximately 0.02 pu, thereby confirming the effectiveness of the proposed control strategy in enhancing overall system stability.