EN
The Lingzhou-Shaoxing ±800kV UHV DC Transmission Project
Dec.15.2025
"Lingshao Line" is a core channel of China's "West-to-East Power Transmission" strategy. Originating from Ningdong Converter Station in Ningxia and terminating at Shaoxing Converter Station in Zhejiang, it has a total length of 1,720 kilometers, a rated transmission capacity of 8 million kilowatts, and a designed annual power transmission capacity of 50 billion kWh, undertaking the key mission of cross-regional supply of clean energy from northwest to east China. As the core insulator supplier of the project, Nanjing Electric, relying on the technical accumulation and customization capability of its "Leidian Brand" glass insulators, supplied UHV RTV DC insulator strings, which have become the "safety cornerstone" ensuring the stable operation of the line across extreme environments in 6 provinces.
Targeting the multiple complex environments along the Lingshao Line, Nanjing Electric implemented precise technical adaptation: for differentiated scenarios such as arid sandstorms in Ningxia and icing in high-altitude mountainous areas of Anhui and Zhejiang, customized series insulators such as LXZP-300/550 were developed, adopting an optimized "large umbrella diameter + deep rib skirt" structure, with pollution flashover voltage 40% higher than the national standard, while the dielectric loss value was controlled below 0.02% through a special glass formula; high-strength insulator strings were exclusively developed for the Yangtze River large-span section (span 2,269 meters, tower height 280.2 meters), with a single string bearing capacity of 300kN, passing the ±1,000kV lightning impulse test, adapting to the strong wind load and insulation requirements of the large-span section; aiming at the icing hazard in high-altitude passes such as Lin'an in Zhejiang, the insulator strings are compatible with the DC de-icing system, and can achieve a temperature rise of 8℃ within 15 minutes with the support of UAV de-icing technology, completely solving the risk of icing-induced wire breakage in winter.
In this project, Nanjing Electric supplied a total of over 30,000 insulator strings, covering key areas such as the exit section of Ningdong Converter Station, the core section of the Yangtze River large-span, and the Zhejiang load access section. Since commissioning in 2016, the insulator strings have operated safely for more than 9 years, successfully withstanding 37 severe sandstorms and 22 rain-snow freezing weather events, with the zero-value self-breaking rate always controlled within 0.01%, far exceeding international standards. Their stable operation supported the Lingshao Line to transmit 55.72 billion kWh of electricity in 2024, with a cumulative transmission volume exceeding 393 billion kWh, equivalent to reducing carbon dioxide emissions by 360 million tons. This not only ensures nearly 1/10 of Zhejiang's electricity demand, but also demonstrates the global leadership of China's UHV insulator technology.