Power distribution line single-phase earth fault positioning and isolating method

Abstract

The invention provides a power distribution line single-phase earth fault positioning and isolating method, which comprises a characteristic frequency constant current signal source, a fault positioning indicator and a fault isolating switch, wherein the characteristic frequency constant current signal source is connected to a distribution network neutral point, and a characteristic frequency constant current signal is injected into a distribution network through a neutral point; the fault positioning indicator and the fault isolating switch are connected to a power distribution line, and detect and determine the characteristic frequency constant current signal on the power distribution line, and when the power distribution line is subjected to single-phase earth fault, the detected signal amplitude exceeds the set threshold, further the fault positioning indicator alarms, the fault isolating switch acts. Through the power distribution line single-phase earth fault positioning and fault isolating method provided by the invention, the difficulties of lower flexibility and accuracy in determining the single-phase earthing fault aspect with higher transition resistance can be overcome, thus the reliable positioning indication and fault isolation of the single-phase earth fault of a distribution network can be realized, and the reliability, economy and safety of distribution network power supply can be improved.

Description

technical field [0001] The invention relates to a fault location and fault isolation method for a power distribution line, in particular to a single-phase ground fault location and fault isolation method for a power distribution line. Background technique [0002] The number of lines in the 10kV distribution network is large, the network structure is complex, and the incidence of single-phase ground faults is high. At the same time, there is no obvious signal feature as the criterion for ground fault indication and isolation. For many years, when a ground fault occurs on the line, it is still necessary to search along the line manually, which increases the difficulty of fault finding, fault isolation and troubleshooting time. At present, there are also some devices that can realize the location indication of the single-phase ground fault section of the distribution network, but in related devices, when the transition resistance of the single-phase ground fault point is high,...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to improve the sensitivity and accuracy of single-phase ground fault location and isolation when the transition resistance of the single-phase ground fault point in the existing device is high Provides a method for single-phase-to-ground fault location indication and fault isolation of distribution lines without high difficulty

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