Abstract:

Silicone rubber insulators have good hydrophobicity and anti-pollution flashover ability, so they play an important role in transmission and transformation external insulation equipment. In order to study the insulation performance of silicone rubber insulators with various extreme weather, the extreme weather conditions such as low temperature, ultraviolet radiation and acid rain are simulated artificially in the laboratory. Then the silicone rubber insulation specimens obtained from composite insulator products are studied experimentally. The influence of several special climate conditions on surface hydrophobicity is analyzed by measuring the static contact angle of the silicone rubber specimens during the experiment. The experimental results show that low temperature can improve the hydrophobicity of silicone rubber insulator surface, and the static contact angle increases by about 23.2% after 240 hours at -40℃. Both ultraviolet radiation and acid rain can accelerate the aging of insulator surface materials, thus weakening the hydrophobicity of silicone rubber surface. After 336 hours of ultraviolet radiation, the static contact angle of the specimen surface decreases by more than 60%. Under the acid rain condition of pH≈5.6, after 336 hours, the static contact angle decreases by about 12%. The decrease of the static contact angle of the surface represents a decrease in the hydrophobic performance, which will directly affect the insulation performance of the silicone rubber composite insulator, resulting in an increase in the probability of contamination. The conclusions can bring reference to the operation and maintenance of composite insulators.

Key words: Composite insulator, low temperature, ultraviolet light, acid rain, static contact angle, surface hydrophobicity