In fault ride through (FRT) period, the stator side of double feed induction generator (DFIG) will generate a transient flux, which may cause the rotor overcurrent and the DC bus over voltage. The demagnetization control is an effective method to accelerate the decay of stator transient flux. But the effect of traditional demagnetization control is not ideal. In this paper, the transient model of DFIG is derived first. Then, an optimized demagnetization control strategy is proposed, and the performance of the proposed strategy is analyzed. The simulation results of a 2 MW DFIG system in DIgSILENT/Power Factory software validate that the optimized demagnetization control strategy can accelerate the decay of stator transient flux more effectively than the traditional demagnetization control strategy.

DFIG,Demagnetization Control,FRT,Rotor Transient Current,Stator Transient Flux