Research on the value of crowbar resistance to low voltage ride through of DFIG

When the major failure of power grid happened, the network voltage dropped and the line current increased rapidly, which caused the rotor current of DFIG improved and the DC bus voltage increased that threatened the safety of power electronic device. Some measures are proposed to help DFIG ride through low voltage fault. Aiming at voltage drop sharply, the crowbar protection circuit is used widely in wind power plant. In this paper, the crowbar protection circuit is studied and the value of crowbar resistance is calculated. The simulation results show that DFIG have the best low voltage ride through (LVRT) ability with the optimum value of crowbar resistance.