LAUSR

The surface charge accumulation on polymers can reduce the insulation performance of the materials and even cause surface flashover. The characteristics of surface charge accumulation and dissipation for epoxy resin (EP) exposed to various nanosecond pulse voltage parameters (i.e. pulse rise time, pulse width and voltage amplitude) are investigated. The results show that the fractional decay of surface charge increases with pulse rise time and decreases with pulse width and voltage amplitude. However, abnormal dissipation phenomenon appears when the pulse voltage reaches 9 kV. Analysis suggests that the abnormal dissipation phenomenon can be attributed to surface charge transport primarily along the surface. Furthermore, the surface charge fractional decay is less than 30% for a dissipation time of 30 min under different nanosecond pulse voltage parameters. In addition, the method of atmospheric pressure plasma jet (APPJ) is utilized to deposit SiCxHyOz thin film on the surface of epoxy resin (EP) samples. It is found that the fractional decay of surface charge for treated EP samples is promoted approximately by an average of 90%. The trap density distribution indicates that the shallow traps that are formed by APPJ treatment result in a decrease in the trap energy level.