Graphene Oxide Addition With Low Fraction Improving Surface Charge Inhibition Performance of Epoxy/SiC Coating Under DC Stress

Surface charge accumulation under DC stress is a critical factor in reducing the insulation performance of epoxy-based nanocomposite. Surface coating has been used to inhibit the charge accumulation, but the inhibition mechanism of the coating material is still unclear. In this paper, graphene oxide (GO) and silicon carbide (SiC) have been selected as fillers to prepare the coating material with epoxy as the base material. The role of GO on surface charge inhibition performance of epoxy/SiC coating has been estimated. The test results showed that the charge inhibition performance and the flashover voltage increase with the growth of nano-SiC content from 1 wt% to 5 wt% in the epoxy/SiC coating. As regards the epoxy/(SiC+GO) coating, the charge inhibition performance and flashover voltage reduce as the SiC content increases. It is suggested that the charge inhibition performance of epoxy/SiC coating can be improved with a low content addition of GO. The variation of trap distribution in the coating material caused by the GO should be responsible for the enhanced charge inhibition behavior.