Reliability Study of Fluorosilicone Rubber Composite Insulators under Strong Radiation and Low Temperature

Composite insulators have many advantages such as light weight, high flashover voltage and self-cleaning. However, silicone rubber(SiR) composite insulators are prone to aging in strong radiation and low temperature environments. To improve the reliability of the power grid, fluorosilicone rubber(F-SiR) composite insulators are selected as the main object of this study. The electrical performance of the two types of composite insulators is compared. The study shows that the contact angle of the fluorosilicone type is still larger than that of the SiR type after both types undergo 2000h UVA-340 Ultraviolet(UV) aging. It shows better water repellency and radiation resistance. Meanwhile, the Shore A hardness of the fluorosilicone type decreased by 0.68%, while that of the SiR type increased by 5.40%. -CF3 group absorbed radiation energy instead of -CH3 group in XPS detection. For both types of insulators, the leakage current values of both are comparable at -30-20 degrees C environment. In particular, the leakage current of fluorosilicon type is lower when it rises from below zero to above zero. For the plateau area with large temperature difference between day and night, low temperature, and strong light radiation. The use of fluorosilicon type insulators will extend the service life of composite insulators. A more important point is to improve the reliability and economy of the power grid.