Porcelain insulators are electrical equipment insulation components made of electrical ceramics, primarily composed of high-purity alumina and zirconium oxide. Their structure includes an iron cap, porcelain body, and steel feet, assembled using cement bonding. They possess high-temperature resistance, pressure resistance, and corrosion resistance, and are used for external insulation of high-voltage transmission lines and power station equipment. They are classified into three categories according to their application: those for transmission lines, those for power station equipment, and those for other live conductors.
These insulators mainly include feldspar porcelain, silica porcelain, and alumina porcelain types, suitable for low-voltage lines, high-voltage levels, and high-strength applications, respectively. In power systems, they perform conductor isolation, support, and fixation functions, requiring high mechanical strength, high insulation strength, and adaptability to complex environments. In the ultra-high-voltage transmission field, a cylindrical head structure design is used, with performance stability improved through optimized alumina formulation and automated molding processes.
Porcelain insulators were first used in telegraph lines in 1849. With the development of ultra-high voltage (UHV) power grids, related manufacturing technologies have made progress in processes such as semiconductor glaze, and related products have achieved industrialized production and have been applied in numerous UHV transmission projects both domestically and internationally. The continuous development in the UHV field has driven the upgrading of porcelain insulator production capacity and technology, with constant innovation in its manufacturing processes. Domestically produced large-tonnage suspension porcelain insulators for UHV have seen improvements in their electromechanical destructive performance through structural optimization and process improvements.
