China’s Insulator Technology: A Mature Portfolio Supporting UHV Projects

Having withstood extreme environmental conditions including icing, high altitude, pollution, earthquakes and typhoons, China’s insulator industry has developed a mature product portfolio comprising three parallel technology pathways — porcelain insulator, glass Insulator and composite insulator. Multiple manufacturing capabilities have reached internationally competitive levels.

Three Major Insulator Types: Complementary Strengths and Extensive Service Experience

Chinese suspension porcelain insulators have 95 years of operating experience. With a wide range of shed profiles and excellent electromechanical performance, they offer a service life exceeding 30 years, requiring routine maintenance through defect detection.

Suspension glass insulators feature a “zero-value self-explosion” characteristic, eliminating the need for zero-value detection. Their shed design is primarily deep-ribbed, and service life also exceeds 30 years.

Composite insulators are non-puncture type, requiring no zero-value detection. They offer excellent Anti-Pollution performance, light weight, good heat dissipation and explosion-proof characteristics, with a service life exceeding 20 years.

Today, suspension composite insulators, post composite insulators, hollow composite insulators and post porcelain insulators are widely used in AC/DC EHV and UHV transmission and substation projects — a clear recognition of composite insulators’ reliability gained over more than two decades of development.

Manufacturing Capabilities: Internationally Competitive Standards

Suspension Porcelain and Glass Insulators
Full product series have been developed, covering AC 70–530kN and DC 160–530kN, with shed profiles including double-shed and triple-shed designs. Manufacturing technology has reached internationally competitive levels.

Suspension Composite Insulators
First energized in 1988 (AC) and 1995 (DC), key manufacturing technologies have matured. By 2007, the product series covered AC 10–1000kV and DC ±500–±800kV.

Post and Hollow Composite Insulators
A post composite insulator with structural height of 12.27m and rated bending load of 16kN, and a hollow composite insulator with structural height of 10.8m and rated bending load of 45kN, have been successfully developed. The application of high-temperature vulcanized (HTV) silicone rubber has reached world-class levels.

Post and Hollow Porcelain Insulators
Products for 750kV, 1000kV and DC ±800kV have been successfully developed. Among these, the 10m-high post porcelain insulator with a bending failure load of not less than 16kN has achieved world-leading performance. Currently, AC 500–1000kV and DC ±500–±800kV hollow porcelain insulators and bushings are still in the process of domestic localization and are at an internationally advanced level.

Comprehensive Solution for Power System and Environmental Demands

China’s insulator products cover the following applications for overhead lines, substations, converter stations and various electrical equipment:

• Overhead lines: AC 10–1000kV, 70–530kN; DC ±500–±1000kV, 160–530kN suspension insulators (porcelain, glass and composite)

• Post insulators: AC 35–1000kV, DC ±500–±1000kV; bending load 2–25kN; structural height up to 10m or more

• Hollow insulators: For circuit breakers, instrument transformers, power transformers, etc.; structural height up to 10.5m or more; average diameter over 900mm

• Shed profiles: Including standard, aerodynamic, anti-fog, alternating, double-layer and triple-layer designs

Leveraging long-term operational data and continuous manufacturing innovation, China’s insulator industry is steadily advancing the localization of high-end products, providing a solid foundation for the safe and stable operation of power grids under complex environmental conditions and at UHV voltage levels.