CONTROL OF GRID-CONNECTED DFIG WIND TURBINE SYSTEM DURING THE GRID FAULT

Abstract

This research, a control scheme based on a combination of proportional integral controller and resonant regulators has been proposed for the doubly-fed induction generator (DFIG) wind turbine system under unbalanced grid voltage. A model of DFIG wind turbine system with the rotor-side converter (RSC) is firstly analyzed in the synchronous reference frame. Then, the proportional integral plus resonant (PI+R) regulators are utilized. With this combination of the two controllers, the oscillations of the power and generator torque can be much reduced in the transient and steady states. The effectiveness of the proposed scheme is verified by the simulation results for the 2 MW-DFIG wind turbine system under unbalanced grid voltage conditions.