Effects of Plasma Etching on Insulating Performance of Epoxy Resin Considered for GIL Insulator

The flashover along the epoxy insulator surface seriously affects insulating performance. To improve the flashover characteristics of insulators, plasma etching is proposed to change the physical and chemical properties. The plasma etching method can prevent the formation and development process of flashover. In this paper, epoxy insulator surface morphology is observed using SEM. Surface charge behaviors and trap characteristics are researched, and mechanism of the effect of plasma etching is put forward. Then the mechanism is verified by flashover voltage test. In different etching stages, different factors play a decisive role. With the etching time increasing, the surface roughness keeps increasing; the surface charge dissipation is slowed down first, then accelerate and then is slowed down again; the trap depth increases first, then decreases and increases at last; the flashover voltage increases at first, and then decreases and increases again at last. And it can be concluded that etching for 5 min is the best to improve insulation performance.