Mitigation of Subsynchronous Resonance in Series-Compensated DFIG Wind Farm Using Active Disturbance Rejection Control

This paper presents an active disturbance rejection control (ADRC) method to mitigate subsynchronous resonance (SSR) in a doubly-fed induction generator (DFIG)-based wind farm connected to series compensated transmission lines. First, the frequency of the SSR and its influencing factors are analyzed, and the limitation of the traditional damping controller based on phase compensation is discussed. Then, a damping controller is designed using the ADRC method, which is adapted to the uncertainty SSR frequency of wind farms. The stator current of the DFIG that contain apparent SSR frequency is adopted as the input signals of the ADRC damping controller, and the outputs are added to the current inner loop of the rotor side converter (RSC), which has fast response speed. The performances of the ADRC damping controller are tested in different compensation levels, numbers of DFIG in wind farm, and parameters of the converter control. The simulation results indicate that the ADRC damping controller is superior to the traditional damping controller for mitigating the SSR because it can automatically estimate and compensate the uncertainty disturbances.