The Testing Of High Voltage Silicon Carbide Lightning Arresters

Abstract

The majority of high voltage gapped silicon carbide lightning arresters on transmission and sub transmission systems have been in service for over 10 years. A testing program is required that can accurately and efficiently determine the condition of these high voltage arresters. The essential theory of silicon carbide arresters was investigated, focusing particularly on arrester construction, performance and the unique characteristics of high voltage arresters. The effectiveness of available testing procedures was then evaluated and a set of tests selected, based on their expected performance, their ability to assess all facets of arrester behavior, the ease with which they could be completed in the available laboratory and their possible application to in-field testing. The testing program implemented consisted of a series of procedures including the lightning impulse sparkover voltage test, power frequency sparkover voltage test, power frequency withstand test, AC and DC leakage current measurements, 5 kV insulation resistance test, and finally a non-standard current impulse test. The tests were performed on a set of 6 arresters rated at 33 and 132 kV and a set of 5 arrester sections. The results of the investigation verified the effectiveness of the selected procedure with a consistent and accurate assessment of arrester condition obtained for all arresters under test. All arresters exhibited satisfactory performance in the selected tests, indicating that high voltage gapped silicon carbide arresters are more durable than those used on distribution systems.