Protection algorithm for a wind turbine generator in a large wind farm

A protection algorithm for a wind turbine generator (WTG) operating in a large wind farm is described in this paper. To minimize the outage section, the protection should operate instantaneously for an internal fault or a connected power collection feeder fault, whilst remaining inoperative for an internal fault on a parallel WTG connected to the same feeder or an adjacent feeder fault. In addition, the protection should operate after a delay (i.e. as back-up) for an inter-tie fault or a grid fault. A fault on the parallel WTG or the adjacent feeder is discriminated based on the magnitude of the positive sequence current. To distinguish an internal WTG or connected feeder fault from an inter-tie or grid fault, the phase angle of the negative sequence current is used to determine the type of fault and then the magnitude of the positive sequence current is used to decide if the operating response should be instantaneous or delayed. The performance of the protection is verified under various fault scenarios based on EMTP-RV generated data. The results indicate that the algorithm can successfully distinguish faults that require instantaneous operation, delayed operation or non-operation.