Test method of leakage current component of metal oxide arrester

Abstract

The invention discloses a test method of leakage current component of a metal oxide arrester. The method includes collecting the leakage current of the three-phase metal oxide arrester and the voltage of an A-phase high voltage side, wherein the leakage current of the three-phase metal oxide arrester passes through a down lead of the three-phase metal oxide arrester at t sampling time; calculating the phase angle of the voltage of the A-phase high voltage side of the metal oxide arrester; and selecting the sampling time of the voltage waveform of the A-phase high voltage side in any zero crossing point within a fundamental wave period and the voltage waveform of the A-phase high voltage side in the zero crossing point at the sampling time, and calculating the capacitive current component and resistive current component of the leakage current of the three-phase metal oxide arrester according to a mathematical model. According to the method, the influence of interphase coupling capacitance is taken into consideration on the basis of the mathematical model, accurate testing of the entire process of the transient state of the leakage current component of the three-phase metal oxide arrester is realized, the insulation condition changes of the metal oxide arrester can be found in time, and a reliable basis for rapid planning of maintenance schemes of the metal oxide arrester is provided.

Description

technical field [0001] The invention relates to the field of electric equipment protection, in particular to a method for measuring components of leakage current of a metal oxide arrester. Background technique [0002] Due to its superior flow characteristics, metal oxide arresters are widely used as overvoltage protection devices for power equipment. When the metal oxide arrester is damp, the fundamental frequency component of the resistive current in the leakage current will increase significantly; when the metal oxide arrester is aging, the third harmonic component of the resistive current in the leakage current will increase significantly. Therefore, the on-line monitoring of the insulation performance of metal oxide arresters can be realized by analyzing the components of the leakage current of metal oxide arresters. At present, the analysis methods for the leakage current components of metal oxide arresters mainly include the fundamental wave method, the third harmoni...

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Problems solved by technology

At present, the analysis methods for the leakage current components of metal oxide arresters mainly include the fundamental wave method, the third harmonic method, the harmonic analysis method and the capacitance current compensation method. The monitoring accuracy of these methods is affected by the coupling capacitance between phases. The harmonic analysis method Due to the large amount of calculation, the practicability is poor; the fundamental wave method, the third harmonic method and the capacitive current compensation method need to use a cycle data window to calculate the fundamental frequency component of the resistive current and the fundamental frequency component of the capacitive current. The required data window is large and cannot be done. The whole process of transient monitoring of the leakage current composition of metal oxide arresters is not strong in real time

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