On Discharge Inception Voltage for Insulators under Non-uniform Field with AC Voltage

In this paper, an analytical expression has been exploited for computing the discharge inception voltage of polluted insulators under a high voltage AC system. This expression was established for DC high voltage. The present contribution is inspired from the modified Peek's law used for calculating the inception voltage of a typical streamer discharge. An experimental investigation of the electric arc initiation on laboratory physical model using a photomultiplier has been also reported. It was observed that, the threshold voltage rises with increasing inter-electrodes gap and high voltage electrode radius. It decreases with increasing conductivity.