Influence of PD rest time on /spl phi/-q-n patterns from voids

Abstract

To understand the mechanism of transition of PD characteristics with material aging is important for PD diagnosis. In the aging process, two typical /spl phi/-q-n (phase-charge-number) patterns with turtle-like and rabbit-like shapes, respectively, can be observed. In this paper, the effect of rest time on PD behavior is studied by changing the shape of the waveform. Comparative study on PD from a void between two metal surfaces is also carried out, in which the discharge area of every PD is equal to the metal surface, and the influence of the variation of PD discharge areas can be neglected.