Power distribution network cable aging state on-line monitoring and early warning device

Abstract

The invention provides a power distribution network cable aging state on-line monitoring and early warning device. Basic principle is a homogeneous comparison method; and the on-line monitoring and early warning device comprises a sampling transformer, a cable sample, a current transformer, a leakage current meter and a signal processing unit. The characteristic quantity reflecting the aging stateof a cable is obtained by recording cable voltage action time and leakage current and carrying out comprehensive operation; and when the characteristic quantity exceeds a certain range, an alarm is given to avoid sudden major cable accidents.

Description

technical field [0001] The invention relates to a cable early warning device, in particular to an on-line monitoring and early warning device for cable aging status in a distribution network. Background technique [0002] The present invention is aimed at the status monitoring and early warning of distribution network cables. The cables mentioned in the full text refer to distribution network cables unless otherwise specified. The insulating material is generally cross-linked polyethylene, and the model is YJLW series. [0003] With the development of my country's power grid and the transformation of urban power grids, the scope of use of power cables has expanded, and they are also widely used in distribution networks. However, once the cable fails, it is difficult to quickly find out the exact location of the fault point. Failure to eliminate faults and restore power supply in time often results in heavy losses caused by power outages and production shutdowns. The basic ...

AI Technical Summary

Problems solved by technology

[0005] One is that it is necessary to continuously apply a voltage several times higher than the operating voltage, which is likely to cause damage to the cable and introduce new defects;

[0006] Second, there are only two types of withstand voltage test results: pass and breakdown, and some hidden defects are not easy to be found, and it is not conducive to the evaluation of the insulation state;

[0007] The third is that the visualization of the test process of the existing voltage withstand equipment is not enough, and it is impossible to link the partial discharge with its occurrence location

However, the various existing aging assessment models are limited to theoretical and practical verification, and their credibility is insufficient.

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