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

Summary

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 post insulators with surface defects are produced, and PD tests using both UHF method and pulse current method are carried out on these insulators in a GIS model. Time difference of arrival is obtained with multiple sensors installed in the hand holes to eliminate the interference in the experiment site. The results show that both the cracks in the basin-type insulator and the surface defect on the post insulator tested in the experiments can induce PD phenomenon, but the PD characteristics show great differences depending on the type of the defect and the voltage supplied.

Additional informations

Authors

Klys Pawel, KOPPLIN, Kuniewski Maciej, Pajak Piotr, Li Xiandong, Li Hua