Pilot protection of new energy field station transmission line based on Kendall correlation coefficient

Abstract

Abstract In order to solve the problems of mis-actuation and rejection based on the protection method of industrial frequency quantity, a new pilot protection method applicable to the new energy field station sending out line is proposed to ensure the reliable operation of the new energy grid-connected system and the sending out line. The fault transient current characteristics of synchronous generator and inverter power supply are analyzed, and it is concluded that the fault transient current waveforms of the new energy side and the system side have obvious differences when the in- and out-of-area faults occur in the transmission line, and the new longitudinal protection method based on the Kendall correlation coefficient is proposed by using the improved soft-threshold wavelet packet network method for preprocessing of the sampled data. The simulation results show that the proposed new protection method can reliably and sensitively recognize various types of faults inside and outside the new energy field station sending line area, and has strong noise immunity and tolerance to transition resistance.