Method for measuring equivalent inductance of coupling capacitance loop under lightning over-voltage and system thereof

Abstract

The invention provides a method for measuring equivalent inductance of a coupling capacitance loop under lightning over-voltage and system thereof, wherein the method comprises the following steps of: obtaining an equivalent capacitance value and an equivalent resistance value of the coupling capacitance loop on a to-be-measured transmission line; obtaining a sampling value of response current onthe coupling capacitance loop, when an amplitude of the sampling value exceeds the predetermined value, calculating an oscillation period of the response current; and calculating the equivalent inductance of the coupling capacitance loop according to the equivalent capacitance value, equivalent resistance value and the oscillation period of the response current. The method and system for measuring equivalent inductance of the coupling capacitance loop under the lightning over-voltage provided by the invention can self-diagnose coupling capacitance stray parameters of a transforming plant withthe voltage level more than 110kV under the lightning over-voltage. The response current of the coupling capacitance loop is measured by mounting a Rogowski coil current measuring device; as the Rogowski coil current measuring device does not have direct electrical connection with the current loop of the measured transmission line, the Rogowski coil current measuring device is favorable to safe and reliable operation of the transforming plant.

Description

technical field [0001] The invention relates to the technical field of parameter self-diagnosis of a coupling capacitor loop under overvoltage of a transmission line, in particular to a method for measuring equivalent inductance of a coupling capacitor loop under lightning overvoltage, and an equivalent inductance of a coupling capacitor loop under lightning overvoltage measuring system. Background technique [0002] With the rapid development of the national economy, higher requirements are put forward for the safety and reliability of power grid operation. According to relevant statistics, lightning overvoltage intrusion waves are one of the main causes of substation accidents, which seriously affect the safety of power grids. run efficiently. Although the lightning overvoltage has a short action time, its peak value is high and its waveform is steep, which will cause irreversible damage to the insulation of electrical equipment in the substation. The accumulation of dama...

AI Technical Summary

Problems solved by technology

[0003] However, the inductance parameter value in the coupling capacitor circuit is very small, generally only at the microhenry level, and cannot be directly measured, so it is difficult to monitor the lightning overvoltage on the transmission line

Images