Method and system for measuring partial discharge

Abstract

Prior to the measurement of partial discharge, a voltage detected by the antenna is inputted into a spectrum analyzer, a phase difference between an operating voltage and a power supply of the spectrum analyzer is obtained by phase domain analysis using the spectrum analyzer. Based on the phase difference and the voltage phase shift associated with input impedance of the signal converter circuit, the time axis displayed on the screen of the spectrum analyzer is compensated. After the compensation has been carried out, the voltage detected by the antenna is inputted into the spectrum analyzer, the partial discharge pattern which synchronizes with the operating voltage is measured by phase domain analysis using the spectrum analyzer.

Description

CLAIM OF PRIORITY [0001] The present application claims priority from Japanese application serial no. 2004-44926, filed on Feb. 20, 2004, the content of which is hereby incorporated by reference into this application. FIELD OF THE INVENTION [0002] The present invention relates to a partial discharge measurement method and a system, and specifically to a partial discharge measurement method and a system suitable for measuring partial discharge which results from an insulation defect in a container filled with insulating gas used as an insulation material. BACKGROUND OF THE INVENTION [0003] The gas insulated device, such as a gas circuit breaker, gas insulated switchgear and gas insulated bus, which is used in a transmission and delivery system is structured such that a high-voltage conductor is encased in a sealed metal container filled with an insulating gas and is supported by an insulating support medium. If a defect, such as a metal particle, is present in the sealed metal contai...

AI Technical Summary

Benefits of technology

[0007] To achieve the above objective, when measuring partial discharge by using a measuring instrument which displays input information on its screen, the present invention detects voltages of the conductor encased in the container; converts the waveform of the operating voltage (alternating voltage), among detected voltages, applied to the conductor by using a signal converter circuit; inputs the converted operating voltage into the measuring instrument; detects the phase difference between the measuring instrument's power-supply voltage and the operating voltage based on the inputted operating voltage; compensates the phase of the time axis displayed on the measuring instrument's screen according to the detected phase difference; and inputs the detected voltage into the compensated measuring instrument as it is, thereby displaying partial discharge information on the measuring instrument's screen. In this case, if there is a voltage phase shift associated with input impedance of the signal converter circuit, it is possible to further accurately compensate phase shifts by considering the voltage phase shift and compensating the phase of the time axis displayed on the screen of the measuring instrument.

[0008] According to the present invention, partial discharge can be accurately measured.

Problems solved by technology

Accordingly, if the signal which has had its phase changed is processed in the signal processing section, even if a partial discharge signal is detected by using an alternating voltage (operating voltage) as a trigger, it is difficult to detect an accurate pattern of the partial discharge signal.

Images