Hydrophobicity transfer characteristic of silicone rubber is a reason for electrical equipment to protected from the pollution flashover accidents

however the presence of oil will increase the accumulation of pollution. When the oil is leaking

the oil will cover the surface of silicone rubber in the form of oil film

and the contamination accumulates to form a layer of sludge. The hydrophobicity transfer characteristic of silicone rubber will be greatly affected and the withstand voltage will be changed. In this paper

the aged HTV of oil-immersed compound casing is studied though thermal aging

and the effects of oil on the hydrophobic transfer characteristics of HTV are studied by artificial coating. And the influence of surface oil on the pollution flashover voltage of silicone rubber is studied through flashover test. The results show that after aging

holes and gully appeared on the HTV surface

and the interior structure becomes loose

which influence the transfer path of LMW. Hydrophobic performance of steady-state deteriorated. After smearing oil

the aging silicone rubber has higher initial hydrophobicity but worse steady hydrophobicity.And its pollution flashover voltage decreases with the increase of fouling.