Partial Discharge Detection and Discharge Type Identification of Gas Insulated Switchgear Based on Photoelectric Detection

Abstract

Gas insulated switchgear (GIS) is a relatively common high-voltage substation equipment. Due to the internal complex structure and integrated switch, it is easy to cause insulation defects, burrs and partial discharge of metal particles, thereby reducing the insulation of equipment performance, which has attracted the attention of many researchers. In this study, aiming at the problem of partial discharge in GIS, a detection device of partial discharge based on photomultiplier instrument is proposed. In this device, Zemax software is used to simulate a front-end optical signal receiving module that enhances the photosensitive surface and enhances the optical signal aggregation effect. In terms of signal processing, the output voltage signal of the photomultiplier instrument is filtered, and the corresponding signal is extracted for amplification. The partial discharge detecting device designed in the experiment is used to judge the internal insulation defects of the GIS, and to discriminate the metal protrusion defects, the metal particle defects on the insulator surface, the free metal particle defects, and the air gap defects between the insulator and the high voltage conductor, respectively. The partial discharge signal ϕ-u-v spectra of different defect models are constructed. Through the image simulation of partial discharge signals corresponding to defects, it is verified that the detection device can distinguish the partial discharge caused by different defects, which is helpful to prevent the occurrence of malignant discharge accidents and maintain the stable operation of GIS equipment.