Lightning impulse breakdown path and characteristics with dielectric BMC barrier inserted sphere‐plane electrode

Abstract

This study deals with the electrical breakdown characteristics of the sphere‐plane electrode system with the dielectric barrier of bulk moulding compound (BMC) material under the positive lightning impulse voltage. The sphere electrode has a spherical shape of 50 mm in diameter and suspended with a metal rod of 10 mm in diameter, while the plane electrode has a circular with a diameter of 350 mm. The dielectric barrier has a square plate shape of BMC material, and the dimension is changed from 80 × 80 to 240 × 240 mm2. Experimental results show that electrical breakdown paths could be identified into three categories, depending on the dielectric barrier position and the dimension. The larger and farther away from the sphere electrode the dimension of the dielectric barrier is, the occurrence probability of electrical breakdown through the penetration of dielectric barrier becomes. It was confirmed that the breakdown voltage considerably depends on the dimension of the dielectric barrier and the dielectric barrier position.