Nonlinear Conductivity and Surface Charge Decay Characteristics of SiC/Epoxy Resin Composites

The insulator of the gas insulated switchgear (GIS) is casted with epoxy resin. Under DC voltage, surface area charge accumulation will cause electric field distortion even surface flashover. The effects of different mass fractions of silicon carbide (SiC) on DC conductance and surface charge of epoxy resin were studied. The results show that the conductivity of epoxy resin composites is nonlinear at high field when the content of SIC exceeds 10%. With the increase of SiC content, more shallow traps are introduced, which is conducive to the dissipation of surface charge.