The composite insulator is a special insulation control device that plays an important role in overhead transmission lines.

Composite insulators can be divided into line composite insulators and power stations, electrical composite insulators. It can be divided into rod suspension type composite insulator, needle type composite insulator, cross arm type composite insulator, post type composite insulator, wind deflection type composite insulator, etc.

In the early days, insulators were mainly used for power poles. With the development of science and technology, a large number of disc insulators are slowly developing at one end of the high-voltage wire connecting tower. They are used to increase the creepage distance and are generally made of glass or ceramics, called insulators. Insulators play two basic roles in overhead transmission lines, namely supporting wires and preventing current from being reversed. These two functions must be ensured. Insulators should not fail due to changes in the environment and electrical load conditions that cause various electrical and mechanical stresses. Otherwise, the insulator will not have a significant effect and will endanger the use and overall operation of the entire line.