Pilot protection based on mode distance for transmission line connected to renewable energy station

Affected by the inverter control strategy, fault characteristics of the wind turbine are essentially different from the traditional synchronous power supply, leading to a decrease in sensitivity and even rejection of traditional differential protection. In view of the above problems, this paper studies the fault current waveform distinction between the wind turbine and the synchronous power supply, and uses the mode distance to measure the current waveform difference. The simulation experimental system is built and the results show that the mode distance can reliably identify the faults in and out of the area in various fault scenarios, effectively working out the kinks of the degradation of the differential protection.