Thermal and voltage distribution along insulator strings with semiconducting RTV coatings

Icing problems led a great damage to the power network over the world recent years and a lot of ways dealing with this problem are proposed. Semiconducting RTV coating applied to insulators was first put forward in 2007 and it makes a significant role in defeating the ice accretion on insulator surface. It's main advantage in anti-icing are combination of hydrophobicity and hydrophobicity transfer based on the ordinary RTV and the Joule heating effect created by the leakage current. This paper focus on the distribution of voltage and the heat effect of the semiconducting RTV applied to suspension insulator during freezing condition. The thermal distribution along the insulator string with semiconducting RTV coating applied with service voltage in cold condition is investigated using an infrared FLIR. And the distribution of the 7-units 110kV insulator strings is calculated by using finite element analysis. Results showed that the range of the resistance of the semiconducting RTV applied on insulator as a coating is about 106∼107 Ω can get a suitable temperature rise during the cold condition and the voltage distribution is uniform with semiconducting RTV.