Discharge condition and surface charge distribution under repetitive bipolar impulses

This paper discusses behavior of partial discharge (PD) under repetitive bipolar impulse voltage. Using different waveforms of square voltages, PD inception and elimination voltages (PDIV/PDEV) have been investigated in detail on 50 /spl mu/m air gap between J-shaped enameled wire and plane electrode with polyimide film. The change of charge on the capacitor in series with samples is found as good index for PD occurrence under repetitive impulses. The surface charge distributions are also measured to discuss the change of discharge condition under repetitive square voltages.