Partial Discharge as Threat to Insulation of High Voltage Direct Current Transmissions

Abstract

An experimental study of partial discharges that occur in a sample of insulation at alternating current voltage and equivalent direct current voltage was carried out. The resulting oscillograms demonstrate the main differences between partial discharges at alternating current and direct current voltage for dry and moistened insulation. It was shown that insulation moistening is more unfavorable for insulation at direct current than at alternating current voltage. The performed studies are aimed at increasing the dielectric strength of the insulation of high voltage direct current transmissions as one of the key components of the Smart Grid.