Control scheme for grid-connected dfig wind turbine system under grid voltage unbalance

Abstract

A novel control scheme tbr power converters of doubly-fed induction generator (DFIG) wind turbine system has been proposed to mitigate the current oscillations duc to grid voltage unbalance. With this proposed scheme, the current controller is designed in the synchronous reference frame and composed of a proportional integral (PI) controller and a repetitive controller. Thus, the proposed controller gives better performance of the DFIG wind turbine system, compared with the existing dual PI one. The validity of this control scheme has been verified by the simulation of the 2MW-DFIG wind turbine system.