Observations of intrinsic and UV-light initiated partial discharges (PD) in thin polyethersulfone (PES) foils

Abstract

The present work demonstrates a simple method for recording intrinsic partial discharge (PD) activity in thin polyethersulfone foils as a result of electrical stress. The polarity of the PD current is opposite to that of the applied voltage, or that previously applied, to the HV voltage electrode. Partial discharges were also initiated by exposure to UV-light from a laser source. These initiated discharges are delayed for 20 to 50 ns in relation to the excitation pulse. The discharges are attributed to the presence of gas filled voids.