Detection of void in epoxy resin by partial discharge measurement under γ-ray irradiation

In insulation diagnosis it is very important to detect voids in electrical insulation. In this paper, a trial to detect voids was made in terms of measurements of partial discharge characteristics and scanning of a narrow γ-ray beam. The experiments were performed under the application of power frequency voltage and very low frequency voltage. When we take advantage of the change of partial discharge characteristics caused by γ-ray irradiation to a void, there is a high possibility of establishing a new detection method of voids in insulators using conventional partial discharge measurements under low frequency voltage application and scanning of the narrow γ-ray beam