The different stages of PRPD pattern for positive point to plane corona driven by a DC voltage containing ripple

Abstract

The different phase resolved partial discharge patterns, which can be recognized when a positive dc voltage containing a ripple due to a half-wave rectification is used are presented in this paper. Results are given from corona onset to the appearance of breakdown streamers. The outcomes are five different patterns, which represent the four stages of positive corona and their transition zones. Three of them are clearly identifiable with respect to patterns from other discharge sources that have already been reported for dc voltages containing a ripple. For an assessment of pattern formation discharge pulses as recorded at the test object are presented. Finally, the appearance of patterns is explained with support of the measured discharge pulses and the underlying physical processes.