PARTIAL DISCHARGE DETECTION OF CRACKS AND SURFACE DEFECTS IN BASIN-TYPE AND POST INSULATORS IN GIS

Cracks in basin-type insulators are considered to be one of the most severe types of defects in GIS insulation system, and have already caused several flashover accidents in power apparatus. The micro surface defects, which are sometimes ignored in routine test, are considered to be the reason of some flashover accidents on post insulator. However, few works have been done on the detection of these kind of defects, for the difficulty in production, detection and modelling. In this report, the authors mainly focus on the PD phenomenon of the cracks in basin-type insulators and surface roughness on post insulators used in GIS to investigate that whether there is PD phenomenon in these defects, and whether the discharges could be detected by the UHF method. Cracked basin-type insulators and…