According to the voltage dip caused by asymmetric fault, the peak of rotor voltage during the three asymmetric faults is calculated. The root cause of the rotor over current has been revealed combined with the analysis of the control ability of the rotor side converter. On the basis of the maximum control voltage of the rotor side converter, the low voltage ride through area of different asymmetric fault is deduced. The transient model of doubly fed induction generator with crowbar circuit has been built by PSCAD. The low voltage ride through area has been proved to be correct by the simulation results.
