High-resistance grounding fault line selection method based on line transient characteristics

The invention provides a high-resistance grounding fault line selection method based on line transient characteristics, and the method comprises the following steps: 1, fault detection: detecting a neutral point voltage, constructing a zero-sequence voltage change gradient, combining 15% of a conventional phase voltage, setting a corresponding starting threshold value, and taking the starting threshold value as starting of a fault; 2, analyzing the zero-sequence impedance characteristic of each feeder line by using a fault equivalent circuit suitable for high-resistance grounding; 3, analyzing to obtain that after the fault occurs, the sound feeder line is capacitive in the high-frequency band and the low-frequency band, and the fault feeder line is capacitive in the high-frequency band and sensitive in the low-frequency band; and 4, extracting low-frequency and high-frequency components of the transient signal by using a low-pass filter and a band-pass filter, and selecting a fault line by using the correlat