Severity Diagnosis of Surface Partial Discharge Provoked by Immobilized Metal Wire on GIS Insulators

摘要

The surface Partial Discharge (PD) triggered by immobilized metal wire on Gas Insulated Switchgear (GIS) insulators in terms of the discharge phenomena alongside its evaluation process was researched in this paper. With the application of gradually increased voltage, long-term tests were conducted on a well-established 252kV GIS experiment platform to observe the entire evolution process of PD from its very initiation till the eventual flashover. Ream-time measurement was undertaken during the tests to capture the trend curve as a result of test time. The results indicate that PD initiated by defects in GIS can be classifitd into three severity levels, namely, petty discharge, medium discharge, and threatening discharge. Moreover, a procedure based on k-means cluster analysis is proposed to diagnose and assess the severity of PD automatically.