Measuring method of transient value of arrester resistive current and capacitive current

Abstract

A method for measuring the transient values of a resistive current and a capacitive current of a lightning arrester, comprising: firstly, collecting a leakage current sampling value of a grounding down lead of a tri-phase lightning arrester and a voltage sampling value on the high-voltage side of an A-phase lightning arrester at each sampling time; computing the phase angle of the fundamental frequency voltage of the voltage on the high-voltage side of the A-phase lightning arrester, the amplitude value of the fundamental frequency voltage, the phase angle of a triple voltage harmonic wave and the amplitude value of the triple voltage harmonic wave by using a Fourier algorithm; and taking into account the influences of the triple voltage harmonic wave and an interphase coupling capacitance and computing and obtaining the transient values of a capacitive current and a resistive current in a leakage current of a tri-phase metal oxide lightning arrester. The method takes the influences of a triple voltage harmonic wave and an interphase coupling capacitance into account on a mathematical model, realizes the accurate measurement for the transient process of a resistive current and a capacitive current in a leakage current of a tri-phase lightning arrester, realizes the shortening of the monitoring time point of the insulating property of the tri-phase lightning arrester at each sampling time, and provides a reliable basis for finding the dynamic change condition of the insulating property of the lightning arrester and quickly formulating the overhaul scheme of the lightning arrester.

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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