Graphene Nanoplatelets Effect on Electrical Tree Inhibition in Epoxy Resin Insulator

Abstract

Epoxy resin is widely used in high voltage insulator material because of its high dielectric strength. Electrical tree phenomena are one of an electrical insulation degradation. It is easily initiated due to the distorted high electrical field. In this study, graphene nanoplatelets (GNPs) with the contents of 0.003-0.010 wt.% (2.6-8.8 mg) were filled into epoxy resin to improve electrical tree inhibiting ability. Treeing experiments were conducted at a fixed voltage of 15 kV, 50 Hz. LCD digital microscope was used to observe the electrical tree inhibition of GNPs in epoxy resin. The digital image of insulators sample was then analyzed by MATLAB program. The percentage of electrical tree damages of GNPs content of 0.007 wt.% was found at 2.75 %. Experimental results showed that electrical tree has propagated from main branch tree to many small branches. The distributed electrical tree around the main branches occurred after the addition of GNPs. Filling GNPs content of 0.005 wt.% will result to a complex branch tree structure with much longer branches than others. Nevertheless, the average tree length was inhibited at the GNPs filling contents of 0.003 to 0.007 wt.%.