Lightning arrester resistive current and capacitive current transient value measuring method

Abstract

The invention discloses a lightning arrester resistive current and capacitive current transient value measuring method which includes that leaked current sampling values of a three-phase lightning arrester grounding down lead at all sampling times and high voltage side voltage sampling values of an A-phase lightning arrester at all sampling times are collected; phase angle of fundamental frequency voltage of high voltage side voltage of the A-phase lightning arrester, amplitude valueof fundamental frequency voltage, phase angle of tertiary voltage harmonic wave and amplitude value of tertiary voltage harmonic wave are calculated in a Fourier algorithm; influences of tertiary voltage harmonic wave and inter-phase coupling capacitance are considered, and transient values of capacitive current and resistive current in leaked current of the three-phase metallic oxide lightning arrester are obtained through calculation. According to the lightning arrester resistive current and capacitive current transient value measuring method, influences of tertiary voltage harmonic wave and inter-phase coupling capacitance are considered on a mathematical model, accurate measurement of the transient process of resistive current and capacitive current in leaked current of the three-phase lightning arrester is achieved, insulating property monitoring time points of the three-phase lightning arrester are shortened to all the sampling times, and reliable basis is provided for finding lightning arrester insulating property dynamic change conditions and fast making lightning arrester overhaul schemes.

Description

technical field [0001] The invention relates to the field of electric equipment protection, in particular to a method for measuring the transient value of resistive current and capacitive current of an arrester. Background technique [0002] At present, the measurement methods of resistive current and capacitive current in the leakage current of arrester mainly include fundamental wave method, third harmonic method, harmonic analysis method and capacitive current compensation method. The monitoring accuracy of these methods is affected by the coupling capacitance between phases. , the harmonic analysis method is poor in practicability due to the large amount of calculation; 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, and a fundamental frequency data...

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Problems solved by technology

[0002] At present, the measurement methods of resistive current and capacitive current in the leakage current of arrester mainly include fundamental wave method, third harmonic method, harmonic analysis method and capacitive current compensation method. The monitoring accuracy of these methods is affected by the coupling capacitance between phases. , the harmonic analysis method is poor in practicability due to the large amount of calculation; 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, and a fundamental frequency data The window can only calculate a resistive current and a capacitive current value, and it is impossible to analyze and monitor the transient process of the resistive current and capacitive current in the leakage current of the arrester, and the real-time performance is not strong

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