Method utilizing isothermy relaxation current method for evaluating insulated overhead conductor

Abstract

The invention discloses a method utilizing an isothermy relaxation current method for evaluating an insulated overhead conductor, and belongs to the field of testing. The method comprises a numerical control direct current high-voltage power source, a numerical control micro current meter and a control computer. A layer of aluminum foil is arranged outside the insulated overhead conductor. A high-voltage output end of the direct current high-voltage power source is connected with a cable core of the insulated overhead conductor. A high-voltage output end of the numerical control micro current meter is connected with the aluminum foil. The numerical control direct current high-voltage power source and a low-voltage end of the numerical control micro current meter are grounded. A specific high-voltage polarization electric field is exerted on the insulated overhead conductor in advance under normal temperature, after polarization for a period of time, the high-voltage polarization electric field can be removed, and subsequent depolarization relaxation current of an insulating layer of the insulated overhead conductor can be detected. Due to the fact that the depolarization relaxation current comprises abundant insulating material microscopic performance information, parameters such as relevant microscopic parameters, dielectric loss and aging factors of insulating materials can be obtained through relevant analysis, and reliable basis is provided for insulating state evaluation of the insulated overhead conductor.

Description

technical field [0001] The invention belongs to the field of testing, in particular to a testing method for evaluating overhead insulated wires. Background technique [0002] Overhead insulated wire is a technical measure that has emerged in response to the development of urbanization. It has changed from traditional overhead bare wires to wire structures with outer insulation layers such as polyolefin, polyvinyl chloride or cross-linked polyethylene, and has changed from air insulation to solid insulation. , its advantages are significant. From years of operating experience, with the improvement of the insulation rate of distribution overhead lines, the reliability of power supply of distribution lines has been continuously improved, and the failure rate of lines has decreased; effectively solved the contradiction between trees and lines in urban greening, and beautified the city landscape; improve the utilization rate of the line channel; prevent the direct impact of envi...

AI Technical Summary

Problems solved by technology

At present, the insulation performance evaluation of overhead insulated wires is mainly based on conventional measurements such as insulation resistance and dielectric loss, which cannot quickly analyze the insulation status of overhead insulated wires

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