Experimental investigation on partial discharge characteristics of epoxy-nanocomposite as high voltage insulation material

Partial discharge (PD) is a major problem in high voltage (HV) insulation that it can lead to electrical degradation and ultimate failure of the insulation materials. Recent research found that with the use of nanoparticles, the correct combination of nanofiller with resin will enhance the electrical, mechanical and thermal properties of HV insulation. Boron nitride (BN) is a ceramic dielectric material, with high electrical breakdown strength and high thermal conductivity. This research investigated the effects of BN nanofiller on the PD characteristics of epoxy resin, using CIGRE Method II electrode configuration. The PD number, PD charge magnitude, and average of PD charge during the ageing time under HV stress were investigated. Moreover, the degraded surfaces of the tested samples were examined using optical microscopy techniques before and after PD stress. The results revealed that higher BN nanofiller percentage will decrease the PD magnitude, PD number and the PD charge. As a consequence, the degraded area caused by the PD activities decreases as the amount of the BN nanofiller increases.