Nonlinear Conductivity of SiC/Epoxy Resin Composites Dependent on Electric-Field at Cryogenic Temperature

Nonlinear conductive composite insulation has been widely used to uniform the local high electric field of high-voltage direct-current (HVDC) equipment. The silicon carbide (SiC)/epoxy resin composites with nonlinear conductivities has great potential applications in high temperature superconducting (HTS) equipment. In this paper, SiC/epoxy resin composites with different filler loading are fabricated, and the nonlinear conductivity is measured at cryogenic temperature. The results indicate that when the filler loading is higher than 17.32 vol%, the composites present field-dependent nonlinear conductivity (FDC) properties. The nonlinear conductivity shows an increasing trend with filler loading increasing. The studies herein provide the nonlinear conductivity characteristics of SiC epoxy composites to predict and improve the electric field distribution at cryogenic temperature.