Improved Control Strategy of Brushless Doubly Fed Induction Generator during Symmetrical Voltage Dips

This article proposes an improved control strategy of brushless doubly fed induction generator (BDFIG) during symmetrical voltage dips. The dynamic behavior of the pre-fault and post-fault PW flux are analyzed and the effects on the CW voltage caused by the transient PW flux is derived. In order to avoid the CW overvoltage and suppress the oscillation of the PW flux, an improve control method with the compensation term, anti-phase to the transient PW flux, is designed to accelerate the decaying of the transient PW flux. Finally, detailed simulation results are provided to verify the effectiveness of the proposed control strategy.