Diagnosis method for the influence of interphase interference on the live test of metal oxide arresters

Abstract

The invention discloses a method for diagnosing an impact on a metallic oxide arrester electrification test from inter-phase interference. The method includes: acquiring instantaneous voltage values at various sampling times from leads on high-voltages sides of an A-phase metallic oxide arrester and a C-phase metallic oxide arrester, calculating phase angles of instantaneous voltage via the Fourier algorithm, acquiring instantaneous leakage current values at various sampling times from grounding down leads of the A-phase metallic oxide arrester and the C-phase metallic oxide arrester, separating resistive current from instantaneous leakage current, calculating a phase angle of the resistive current via the Fourier algorithm, calculating an interference coefficient, and diagnosing by comparing the interference coefficient with a setting valve. By the method, the impact on the metallic oxide arrester electrification test from the inter-phase interference is accurately diagnosed, if any inter-phase interference leads a metallic oxide arrester electrification test result to be abnormal, the diagnosing result can provide powerful reference to testing workers for accurately analyzing insulating performance of the metallic oxide arresters, and testing workers' judgment error caused by the abnormal testing result due to the inter-phase interference can be effectively avoided.

Description

technical field [0001] The invention relates to the field of electric equipment protection, in particular to a method for diagnosing the influence of phase-to-phase interference on live tests of metal oxide arresters. Background technique [0002] Due to its superior flow characteristics, metal oxide arresters are widely used as overvoltage protection devices for power equipment. During the live test of the metal oxide arrester, due to the impact of the B-phase metal oxide arrester on the leakage current of the A-phase and C-phase metal oxide arresters through the stray capacitance, the grounding down wire flowing through the A and C-phase metal oxide arresters The leakage current becomes larger or smaller, that is, interphase interference will cause the live test results of phase A and phase C metal oxide arresters to be too large or too small. If the interphase interference is very small, the interphase interference has little effect on the live test results of the A-phas...

AI Technical Summary

Problems solved by technology

During the live test of the metal oxide arrester, due to the impact of the B-phase metal oxide arrester on the leakage current of the A-phase and C-phase metal oxide arresters through the stray capacitance, the grounding down wire flowing through the A and C-phase metal oxide arresters The leakage current becomes larger or smaller, that is, interphase interference will cause the live test results of phase A and phase C metal oxide arresters to be too large or too small

If the interphase interference is very small, the interphase interference has little effect on the live test results of the A-phase and C-phase metal oxide arresters. The testers can directly analyze the insulation performance of the A-phase and C-phase metal oxide arresters according to the test results; If the interference is large, the phase-to-phase interference will lead to abnormal live test results of phase A and phase C metal oxide arresters. The testers will make judgments based on the abnormal test results, which is prone to misjudgment, resulting in unnecessary power outages and maintenance, resulting in loss of power supply load

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