A method to reduce DC-link overvoltage of PMSG based WECS during LVRT

Low Voltage Ride-Through (LVRT) is one of the most important grid connection requirements for the wind energy conversion systems (WECS). In this paper, flux weakening control of permanent magnet synchronous generator (PMSG) based WECS is proposed to reduce the DC-link capacitor overvoltage for the enhancement of LVRT during symmetrical and asymmetrical grid voltage dips. The controller is developed based on the proportional resonant (PR) current controller. The proposed method is compared with the braking chopper (BC) based conventional method. Time series simulation results illustrate the validity and effectiveness of the proposed control.