Research of wavelet analysis in hydropower station feeder fault quick detection algorithm

A feeder microcomputer protection algorithm based on Symlets5 wavelet is proposed to address the current situation of long sampling algorithm time in commonly used microcomputer relay protection devices for hydropower station feeders, as well as the increasingly strict timeliness requirements for cutting off faults in modern relay protection devices. Through studying and analyzing the maximum modulus of the high-frequency component waveform of the fault signal reconstructed by Symlets5 wavelet decomposition, it is found that the Symlets5 wavelet algorithm can quickly determine the occurrence of short-circuit faults within 2/n~5/n cycles after the fault occurs, and calculate the amplitude of the signal after the fault occurs. The Symlets5 wavelet algorithm can be used as a criterion for initiating protection algorithms or used in conjunction with other algorithms, which can greatly improve the timeliness of feeder protection devices in cutting off faulty lines, and protect the safety of hydropower station feeder lines.