Fault Ride Through Capability Enhancement of Doubly Fed Wind Generator Using Hybrid Protection Circuits

This paper presents a new FRT control strategy to improve the dynamic response of doubly fed induction generator based wind turbine (DFIG-WT) during grid fault. The proposed control scheme is based on hybrid protection circuits, which comprises an active crowbar circuit, a series dynamic resistance (SDR) circuit, and a DC-link Chopper circuit. A coordinated control strategy is been developed to enable the circuit. This strategy enables the crowbar to disable the rotor side converter (RSC), allowing the rotor overcurrent to path through SDR resistors, and the DC-Chopper is engaged to suppress the overvoltage in DC-Link. Simulation analysis by using MATLAB/Simulink shows that the proposed strategy enhanced FRT capabilities for DFIG in symmetrical voltage dip, protected the power converter, limited the rotor overcurrent, and suppressed the DC-link overvoltage.