Effect of surface roughness of dielectric materials on partial discharge current waveforms

The presence of partial discharge is one of the most prominent indicators of defects and ongoing degradation processes in electrical insulation systems. Lately ns orders partial discharge signal measurements has become of major interest, because the waveforms of partial discharges are changed with the degradation of the dielectric materials. In our studies, it is become clear that sometimes the reversed polarity current with applied voltages has been detected after the same polarity current. In this paper, we investigate that the effect of surface roughness of dielectric materials on partial discharge current waveforms.