Design and Implementation of Crowbar Circuits Combined with Chopper Circuits for LVRT in Wind Farms

Abstract This paper presents the advantages of LVRT technology where a crowbar circuit functions in combination with a chopper circuit. To enhance the low voltage ride-through (LVRT) performance of double-fed wind turbines, the advantage of the crowbar protection circuit, the DC-link chopper protection circuit, and rotor side control (RSC) are combined based on current LVRT technology. The crowbar circuit is fully utilized to protect the rotor circuit from overcurrent and plays the role of the chopper circuit to stabilize the DC bus voltage. In addition, this paper proposes a cooperative control strategy that is used in the control of the protection circuit during LVRT. Simulation results based on PSCAD/EMTDC demonstrate that the proposed method can significantly reduce crowbar switching times and LVRT time, and the control method is simple and feasible.