Suppression of Stator Current Oscillation for Doubly-Fed Induction Generator with Optimized References of Converter Control

To improve the fault ride through (FRT) capability of the doubly-fed induction generator (DFIG), the fault current limiter (FCL) as well as the modified converter control may be adopted as the effective solutions. Coordination between the two schemes is able to further enhance the FRT capability of the DFIG. Aiming at this, optimization to the converter control of the DFIG during the FRT is studied in this paper. A novel control scheme to the converters of DFIG is proposed, which is capable to minimize the stator current oscillation with the optimized current references of the converters, both during the voltage drop stage and the fault recovery stage, so as to realize effective suppression of the stator current oscillation for the whole FRT process. Extending from this, transition to the normal operation of the DFIG is also considered. By adjusting the output of the integral link of outer-loop control, the stator current oscillation is also mitigated in the transition process from the direct current control of the converters applied during the FRT to the conventional dual-loop PI control.