Typical Fault Analysis of Composite Insulators for Transmission Lines in Fujian Province

Composite insulators are important components of conductors and towers. A string break or breakdown occurs will have an extremely adverse impact on power grid security and public safety. This paper summarizes the string breaking and breakdown failures of insulators in Fujian province in recent 10 years, and the typical failures such as brittle fracture, decay-like fracture, string break and core breakdown are analyzed experimentally. The statistical results show that in the past 10 years, a total of 23 breakdowns of insulators above 110kV have occurred in Fujian province, including 12 cases of brittle fracture failures, 7 cases of decay-like fracture failures and 4 cases of core rod break-down failures. According to the characteristics of typical fault cases, it is suggested that the core is made of boron-free fiber resistant acid core with good stress corrosion resistance, and the composite insulator ends are connected by coaxial multi-directional crimping.