Influence of Space Charge Accumulation by Pre-stress on Partial Discharge Inception Voltage

Abstract

Space charge accumulation characteristics in PAI (polyamide-imide), which are used as an insulating layer of motor windings, were observed under applying a rectangular voltage. Furthermore, PDIV (partial discharge inception voltage) in twisted pair wires coated with PAI was also measured by applying the rectangular voltage previously applied with a dc voltage (prestress), which generates the space charge. Since a change of PDIV was observed in the prestressed sample, it was concluded that the space charge accumulation may affect the change of PDIV.