Distribution network single phase earth fault detection method based on transient component

Abstract

The invention provides a distribution network single phase earth fault detection method based on a transient component. The method has the advantages of novel principle, small computational complexity, wide applicability, easy realization and low construction cost. Through zero sequence voltage starting, by use of transient zero sequence voltages and transient zero sequence currents at an initial stage when a fault is generated, after bandpass filtering is performed, the fifth harmonic component of a line and an earth capacitance parameter are calculated, and according to the size of the fifth harmonic component and the positive and negative characteristics of the capacitance parameter, whether a protected line generates a single phase earth fault is identified. The method is free from the restrictions of an earth ground and a line grid structure, can be applied to an overhead line, a cable line or a mixing line, and is good in performance and high in sensitivity. The earth resistance which can be detected reach 1 K ohm, yet in actual engineering application, a fixed value set workload is quite small.

Description

technical field [0001] The invention relates to distribution network fault detection and analysis technology, in particular to a distribution network single-phase ground fault detection method based on transient components. Background technique [0002] At present, in the 10KV distribution network, in order to improve the reliability and safety of power supply and reduce the power outage time and frequency of 10KV feeder, the transformation of urban distribution network continues to expand and deepen, 10KV distribution network feeder automation is widely implemented, 10KV distribution terminal Widely used; and with the spread of the power supply network, cables and overhead lines are distributed in various residential and enterprise power consumption areas in the city, and the distribution area is wide and scattered. The most important functional requirement for 10KV line power distribution terminals is the detection and identification of single-phase ground faults. [000...

AI Technical Summary

Problems solved by technology

[0003] Single-phase ground fault detection technology is mainly affected by factors such as distribution network grounding method, grounding resistance, line material bare wire or cable, line grid structure, etc., each has its own advantages and disadvantages; Line branches are complicated. After the power distribution terminal is put into operation, the line transformation often expands the branch again. The setting of various detection technologies is heavy and difficult. Often, the principle is correct but the detection result is wrong due to inaccurate setting of the value. , the fault location is wrong, resulting in the expansion of the power outage

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