Comparisons of PI and PR current controllers based flux weakening to limit DC-link capacitor overvoltage in PMSG based wind energy system

Abstract

Fault Ride-Through (FRT) is one of the most essential grid connection requirements for the grid connected permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS). A flux weakening method of PMSG based WECS is proposed in this paper to reduce DC-link capacitor overvoltage for the enhancement of FRT during symmetrical and asymmetrical grid faults. The proposed method is developed based on the proportional integral (PI) and the proportional resonant (PR) current controllers. Comparisons of the two current controllers have been presented through time series simulation results. It has been found that PR current controller based flux weakening method shows better performance in limiting Dc-link capacitor overvoltage during grid faults.