Cable Fault Location Method Based on Spectrum Attenuation Characteristics

Abstract

The invention relates to a cable fault point positioning method based on the frequency spectrum attenuation characteristic. The cable fault point positioning method comprises the steps that corresponding local discharge signals are collected at different positions of a cable line correspondingly, and local discharge signal amplitude values are separated; relation curves between the local dischargesignal amplitude values and the positions under different frequencies are fitted; a corresponding intersection point position of the two relation curves when the amplitude values are equal is calculated; the intersection point position serves as a starting point, local discharge signals at different positions are collected on the sides in the opposite directions of the cable line correspondingly,local discharge signal amplitude values are separated, relation curves between the local discharge signal amplitude values and the positions under the different frequencies are fitted, and a corresponding intersection point position of the relation curves when the amplitude values are equal is solved and serves as a local discharge starting point. The cable fault point positioning method is reasonable in design, testing can be conducted under the line outage situation and can also be conducted during line operation, testing can be conducted at the end of the line and can also be conducted from a joint in the middle of the line, the testing result is accurate and convenient, and the applicable place is wide.

Description

technical field [0001] The invention belongs to the technical field of power cables, in particular to a method for locating cable fault points based on spectrum attenuation characteristics. Background technique [0002] With the advancement of power supply system transformation and upgrading work focusing on urban power supply networks, the cable conversion rate of 110kV and above voltage transmission lines is increasing rapidly. seems particularly urgent. Partial discharge, as the main manifestation of cable line insulation failure in the early stage, is not only the main cause of insulation aging, but also the main characteristic parameter that characterizes the insulation condition. At present, the use of partial discharge live detection in the operation of high-voltage cross-linked cable lines is closely concerned at home and abroad. Technology hotspot. [0003] At present, the more effective method for locating cable partial discharge is the oscillatory wave method. T...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, to propose a cable fault point location method based on spectrum attenuation characteristics, to solve the problem of difficult testing and the inability to effectively collect signals due to partial discharge signal attenuation

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