Mitigation of SSCI in DFIG based Wind Farms through Modification of Rotor-Side Converter Controller

This paper presents a mitigation strategy to reduce the risk of Subsynchronous Controller Interaction (SSCI) in Doubly-Fed Induction Generator (DFIG) based wind farms. SSCI mitigation is achieved through the modification of the controller structure within the DFIG turbine. A proportional damping controller tuned to the SSCI oscillatory frequency is proposed and implemented in the current controller loop that regulates the rotor current of the DFIG, aiming at enhancing the system damping at the frequency of interest. Time-domain simulations are used to prove the effectiveness of the proposed controller in reducing the risk of SSCI.