Automatic positioning system for single-phase earth fault of distribution line

Abstract

The invention discloses an automatic positioning system for a single-phase earth fault of a distribution line, which comprises an earth fault indicator, a communication terminal and a master station background, wherein the earth fault indicator comprises a zero sequence CT (Current Transformer) and a acousto-optic warning device and is in remote connection with the master station background through the communication terminal; and the master station background is provided with a communication system. The system has a simple structure, is reliable to operate, and can be used for detecting a fault point of a distribution line quickly and accurately, so that a serviceman can rush to the scene quickly to remove the fault, the normal power supply is recovered, the labor intensity of fault line walkers is reduced, and the working efficiency is improved; and simultaneously, the invention can be directly applied to discovery and location of the earth fault of the distribution line with 10kV or above.

Description

technical field [0001] The invention relates to an automatic positioning system for a single-phase grounding fault of a power distribution line. Background technique [0002] With the transformation of overhead lines in urban distribution networks, more and more overhead lines will go into the ground at urban crossroads or bustling commercial areas, forming a lot of cable overhead hybrid lines. In the urban distribution network, the power supply radius is relatively large, there are correspondingly many branch lines, and the lines are relatively weak, so the line faults are relatively frequent, and it is very difficult to find the branch and fault point where the specific fault point is located, and it can take a few hours or even dozens of hours. Affecting the reliability of power supply will not only cause large direct economic losses to the company, but also bring serious negative impacts on social and economic benefits. [0003] At present, there are also some fault det...

AI Technical Summary

Problems solved by technology

[0008] In view of the characteristics of the small current grounding system, when a single-phase ground fault occurs, the fault signal itself is weak, and is subject to electromagnetic interference and harmonic pollution, resulting in distortion of the obtained signal, which directly affects the selection of fault indicators sex and accuracy

The zero-sequence current method is widely used in cable line ground fault detection. For overhead systems, zero-sequence transformers or zero-sequence current filters are required for single-phase ground fault indication devices that use detection of zero-sequence current changes for single-phase grounding judgments. To sample the change of zero-sequence current, its structure is complex and inconvenient to install, so it cannot be widely used in 10kV overhead lines

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