Porcelain insulators are insulating components for power equipment made from electrical ceramics, primarily composed of materials such as high-purity alumina and zirconia. Their structure consists of a metal cap, a porcelain body, and a steel pin assembled using cement bonding; they offer resistance to high temperatures, pressure, and corrosion, and serve as external insulation for high-voltage transmission lines and power station equipment. They are categorized by application into three types: those for transmission lines, those for power station equipment, and those for other live components.
These insulators primarily include feldspathic, siliceous, and aluminous porcelain types, suitable for low-voltage lines, high-voltage applications, and scenarios requiring high mechanical strength, respectively. Within power systems, they function to isolate, support, and secure conductors, necessitating high mechanical and dielectric strength as well as the ability to withstand complex environmental conditions. In the field of ultra-high voltage (UHV) transmission, a cylindrical head design is employed, with performance stability enhanced through optimized alumina formulations and automated molding processes.
Porcelain insulators were first used on telegraph lines in 1849. With the development of UHV power grids, manufacturing technologies-such as semiconductor glazing processes-have advanced; these products are now mass-produced and utilized in numerous UHV transmission projects both domestically and internationally. Continued growth in the UHV sector has driven upgrades in production capacity and technology, fostering constant innovation in manufacturing processes. Through structural optimization and process improvements, domestically produced high-tonnage UHV suspension porcelain insulators have achieved enhanced electromechanical breaking strength.
