Effect of Defect Location on Decomposition Components Detection in SF6 Gas Under Partial Discharge

Abstract

AbstractPartial discharge (PD) inside gas-insulated power equipment is an important cause of sudden failures such as flashover and breakdown in equipment. In order to study the effect of defect location on decomposition components detection in SF6 gas under partial discharge during the operational conditions of gas-insulated power equipment, a 252 kV full-scale gas-insulated switchgear (GIS) in-situ detection technology experimental platform was built. On this basis, a SF6 gas decomposition components in-situ detection system was constructed. Through continuous partial discharge experiments, the gas chromatograph was used to detect the characteristic components generated by the decomposition of SF6 gas, including CO, CO2, CF4, and C2F6 changing with the defect location. The results show that under the conditions of continuous partial discharge monitoring on site, no obvious formation of sulfur compounds is detected. When organic insulating materials participate in partial discharge, the CF4 content increases with increasing discharge time, and CF4 is expected to be used as the judgment basis of surface discharge in GIS. The amount of C2F6 produced is very large, the C2F6 content increases with increasing discharge time, and the amount of C2F6 produced decreases with increasing diffusion distance. C2F6 is expected to be used as the judgment basis for partial discharge in GIS. The CO content and CO2 content show a decreasing trend and increasing trend respectively with the increase of discharge time, and the change of these two decomposition components decreases with the increase of diffusion distance.KeywordsSF6 gasDecomposition componentDefect locationDiffusion distancePartial discharge