Coordinated control methodology for fault-ride-through capability of doubly-fed induction generators

In this paper a new coordinated fault ride through approach is proposed for wind turbines which are equipped with doubly-fed induction generators (DIFG). The proposed technique suggests a coordinating methodology between the demagnetizing current control method, STATCOM operation of the grid side converter (GSC), Rotor Current Limiter (RCL) method, and reactive power control of the rotor side converter (RSC). The proposed method guarantees a safe operation for both RSC and GSC during grid faults. The simulation results show that the proposed method limits the rotor inrush currents, DC voltage fluctuations, and electromagnetic torque pulsations during the fault and after the fault clearance. In additional to that, it improves the grid voltage profile during faults; hence it allows the DFIG to be connected for longer periods during grid faults.