Research on the material and pollution-flashover properties of hard composite insulators

Composite insulators have been widely used in power system since 1970s. However, silicon rubber insulators at high altitude and in strong ultraviolet radiation condition have an exponentially increasing failure rate because of the aging failure. Meanwhile, silicone rubber insulators are not allowed to be stampeded on, which is inconvenience for installation and maintenance. A new type of insulator has been designed, which is accessible for climbing, and is adapted to the harsh climate and environment in Northwest China. Hard composite insulators are made from hydrophobicity cycloaliphatic epoxy resin material (HCEP) using advanced technology. In this paper, experiments on material properties has been carried out, which shows that HCEP material has good hydrophobicity and hydrophobic migration performance. Such material of hard composite insulator also has better resistance to electrical erosion and tracking than conventional silicone rubber material. Some characteristics have been compared with the regular insulators in flashover voltage gradient. Test result shows that cycloaliphatic epoxy insulator has better anti-pollution-flashover performance, satisfying the relevant anti-pollution-flashover standards.