Composite Insulator for Electric Railway Tracks

The main function of insulators is to achieve electrical insulation and mechanical fixation, for which various electrical and mechanical performance requirements are stipulated. For instance, under the action of specified operating voltages, lightning overvoltages, and internal overvoltages, they should not experience breakdown or surface flashover; under the action of specified long-term and short-term mechanical loads, they should not suffer damage or destruction; after long-term operation under specified mechanical, electrical loads, and various environmental conditions, they should not show significant deterioration; the fittings of insulators should not produce significant corona discharge under operating voltages to avoid interference with radio or television reception. As insulators are widely used, their connecting fittings are also required to be interchangeable. Moreover, technical standards for insulators require various electrical, mechanical, physical, and environmental condition tests, depending on the model and usage conditions, to verify their performance and quality.