Method for detecting insulation defect of high-voltage cable accessory

Abstract

The invention relates to a method for detecting the insulation defect of a high-voltage cable accessory. In the method, hardware comprises a local discharge signal sensor, a local discharge signal acquisition unit and an industrial control computer, wherein the local discharge signal acquisition unit conditions and amplifies a signal acquired from a cable joint by the local discharge signal sensor, extracts a power frequency voltage signal and a local discharge signal and transmits the power frequency voltage signal and the local discharge signal to the industrial control computer through a universal serial bus (USB) communication interface; and the industrial control computer forms a local discharge spectrogram with reference to a power frequency voltage phase to obtain a characteristic parameter of the discharge spectrogram, compares the characteristic parameter with an insulation defect database and detects the existence of the insulation defect in the cable joint and the type of the defect. Compared with the prior art, the method has the advantages of preventing faults from occurring, enhancing the power supply reliability of a cable system and the like.

Description

technical field [0001] The invention relates to a detection method, in particular to a detection method for insulation defects of high-voltage cable accessories. Background technique [0002] As high-voltage and extra-high-voltage power cables are more and more widely used in power systems, how to realize the status detection of these cable equipment and ensure the safe and reliable operation of the cable equipment has become a hot research topic at home and abroad. [0003] In the high-voltage and ultra-high-voltage cross-linked polyethylene (XLPE) power cable system, the cable accessories are all manufactured and installed manually under on-site conditions, and their insulation quality is often lower than the insulation level of the cable body, which is the weak link in the insulation of the cable system. Various insulation defects formed by poor joint construction technology make the electric field distribution in the joint uneven, resulting in partial discharge. Under p...

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Problems solved by technology

At present, there are many XLPE cable partial discharge on-line detection devices developed at home and abroad. Although partial discharge can be detected, the type of insulation defect that causes partial discharge discharge cannot be given, which brings uncertainty to the decision-making of cable equipment maintenance and replacement.

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