Porcelain insulators were first used in telegraph lines in 1849. In the 1990s, the production and finishing of porcelain insulators in China relied entirely on manual hammering. In the early 21st century, to meet the demands of ultra-high voltage (UHV) construction, domestic enterprises began technological breakthroughs. In 2010, companies such as Sinoma Electric Porcelain undertook the development of UHV rod-shaped insulators. Through process improvements, they achieved a high qualification rate for megavolt products, which were successfully applied in early projects such as the Jin-Southeast-Nanyang-Jingmen 1000 kV UHV AC test demonstration project, breaking the foreign monopoly.
The production process subsequently underwent innovation, from "lying flat for natural air drying" to "vertical electric air drying," significantly improving moisture uniformity and production efficiency. The workshop introduced intelligent equipment such as a dual-station fully automatic blank-finishing machine, realizing the transformation from manual hammering to intelligent production. By establishing a research and development center and increasing R&D investment, companies overcame technical challenges in areas such as 550 kV and above circuit breaker resistance sheets, and 750 kV and 1000 kV inorganic bonded hollow porcelain insulators, filling domestic gaps. Sinoma Porcelain Insulators has established a large-scale, fully automated production line and intelligent production management platform for ultra-high voltage and extra-high voltage insulators.
Currently, domestic porcelain insulator technology has reached the international leading level, forming a product matrix covering all voltage levels from 10kV to ±1100kV. Domestically produced products have been successfully applied to major domestic and international power projects such as the Changji-Guquan ±1100kV ultra-high voltage DC transmission project and the Belo Monte ±800kV ultra-high voltage transmission line in Brazil. Sinoma Porcelain Insulators has become a qualified Chinese insulator supplier for the Italian national grid, Terna, and its blue-gray glaze and other series of products are exported to more than 20 countries and regions worldwide.
