Constant voltage-induced intermittent discharge behavior of metal contaminant degradation on the surface of GIS insulators

Abstract

In recent years, there have been many breakdown discharge accidents caused by intermittent discharge in GIS, and there is no effective method to obtain the change characteristics of intermittent discharge defects under constant voltage to breakdown discharge. Based on this, this paper further studies the deterioration and discharge characteristics of intermittent discharge defects in surface metal pollution of GIS insulators under constant voltage, establish a GIS insulator surface metal contamination intermittent discharge degradation test platform. The discharge quantity and UHF signal changes of intermittent discharge defects caused by metal contamination on the surface of insulators under constant voltage were investigated separately under different temperatures and ultra-long discharge times, and realizes the rapid evolution of metal pollution intermittent discharge into breakdown discharge under constant voltage for the first time. The increase in temperature will cause the defect to evolve from an intermittent discharge state to a stable discharge state; With the increase of time, the discharge amount and UHF signal amplitude increase significantly with the development of pollution deterioration, from intermittent discharge to stable discharge, the discharge intensity suddenly surges at about 200min, and finally rapidly develops into breakdown discharge, which is consistent with the breakdown phenomenon observed in the GIS equipment of Wuhu station.