Performance Analysis of Composite Insulators

Composite insulators are widely used in high voltage transmission lines in coast and polluted areas due to excellent pollution flashover resistance, high strength and convenient installation and maintenance. While there are still various kinds of defects such as abnormal temperature rise, aging of materials even fracture in the existing composite insulators which have drawn the close attention of the operation and maintenance department of power grid. In order to realize the basic performance of new composite insulator products in China, specimens from major manufacturers of composite insulators are sampled for mechanical, electrical and physical and chemical testing. The test results show that the composite insulator products meet the requirements overall, but a few of them have micro-interface and macro-interface defects which may cause local heating even fracture under high humidity conditions. At the same time, the raw materials of composite insulator housing from different manufacturers is quite different, which has certain influence on the service life of composite insulator.