Sub-Synchronous Oscillation Mitigation for Series-Compensated DFIG-Based Wind Farm Using Resonant Controller.

The sub-synchronous oscillation (SSO) phenomenon presents a significant risk to the overall safety and stability of power networks, as evidenced by numerous real-world incidents. This paper introduces a novel approach to mitigating SSO in series-compensated transmission lines by employing a resonant controller in conjunction with a control loop for the doubly fed induction generator (DFIG). To begin, the resonant controller is integrated into the converter controllers of the DFIG system to determine the optimal placement that yields enhanced damping characteristics. Subsequently, an analysis is conducted to explore the impact of different parameters associated with the resonant controller on system stability, with the goal of identifying the most suitable parameter configuration. The proposed control strategy is thoroughly evaluated through time-domain simulations and small signal stability analysis, considering various compensation levels, wind speeds, and sub-synchronous control interactions (SSCI). Furthermore, a comparative analysis is performed between the proposed method and a recent SSO damping technique to validate the efficacy and robustness of the proposed approach. The results of the comparison clearly demonstrate the superiority and effectiveness of the proposed control strategy in alleviating SSO. Specifically, the proposed method achieves the shortest SSO damping time across all feasible operational scenarios, thereby reinforcing its practical value and applicability.