The bidding results for glass insulator products in the world’s first ±1,100 kV ultra-high-voltage direct current transmission project—the State Grid Changji–Guquan 1,100 kV UHVDC line—were recently announced. Nanjing Electric (Group) Co., Ltd. won the contract to supply nearly 400,000 DC glass insulators.

The Changji–Guquan ±1,100 kV UHVDC transmission project is currently the world’s highest-voltage, largest-capacity, longest-distance, and most technologically advanced UHV transmission project. It upgrades the voltage level from the current ±800 kV to ±1,100 kV, increases the transmission capacity from 6.4 million kW to 12 million kW, and extends the economically viable transmission distance to 3,000–5,000 kilometers. This project represents a major milestone in State Grid Corporation of China’s ongoing innovation in the UHV transmission field, setting a new global benchmark for power‑grid technology, ushering in a new era of UHV transmission development, and serving as a significant model for the advancement of the Global Energy Internet.

The State Grid’s Changji–Guquan ±1,100 kV ultra-high-voltage direct current transmission project originates at the Jundong (Changji) converter station in Xinjiang and terminates at the Wannan (Guquan) converter station in Anhui. It traverses six provinces and autonomous regions—Xinjiang, Gansu, Ningxia, Shaanxi, Henan, and Anhui—with a total line length of approximately 3,304.7 kilometers. The project has a transmission capacity of 12 million kilowatts and operates at a voltage level of ±1,100 kV. Approval was granted by the National Development and Reform Commission on December 28, 2015, and full-scale construction commenced in May 2016. The Xinjiang section is scheduled to be ready for energization by June 2018.

The construction of the Changji–Guquan Transmission Project is a key initiative to implement the spirit of the Central Symposium on Work in Xinjiang and to advance the Belt and Road Initiative, delivering significant economic, social, and environmental benefits. As the second ultra-high-voltage transmission line dedicated to exporting Xinjiang’s electricity, the project will facilitate the bundled export of thermal, wind, and solar power from Xinjiang’s energy hubs, ensuring a reliable power supply to the East China region while playing a vital role in air pollution control and boosting Xinjiang’s economic growth. Upon completion, the project will annually deliver approximately 66 billion kilowatt-hours of electricity to eastern and central China, reduce coal transportation by 30.24 million tons, and cut emissions by 24,000 tons of particulate matter, 149,000 tons of sulfur dioxide, and 157,000 tons of nitrogen oxides.

According to reports, Nanjing Electric has won bids for nearly 400,000 high‑tonnage DC tempered glass insulators rated at 550 kN and above, with delivery scheduled from April to September 2017. Among the awarded products are over 20,000 units of 840 kN DC insulators, which boast the highest strength rating among comparable products worldwide and represent the first-ever application in both China’s domestic power grid and international grid projects, marking a milestone of epoch‑making significance.

Upon learning of the project’s award, Nanjing Electric promptly established a project command center, with General Manager Shen Qirong personally serving as the chief commander. The company was directed to approach the task with utmost respect and dedication, uphold a spirit of craftsmanship, clearly define roles and responsibilities, and deliver a high‑quality project. By mobilizing the full resources of the enterprise, it committed to completing production and delivery on schedule, ensuring both quality and quantity, thereby providing the highest‑grade products for the Changji–Guquan 1,100 kV UHVDC transmission project and making a new contribution to the construction of this national key project.

Since winning the bid for the State Grid’s Jinping–Southern Jiangsu UHV DC transmission project in 2011, Nanjing Electric has secured a total of 17 UHV projects with both the State Grid and the Southern Power Grid—6 UHV AC projects and 11 UHV DC projects. The cumulative supply of glass insulators for these UHV projects has exceeded 3.2 million units, placing the company first in China’s industry and contributing to the construction of key national projects such as “West-to-East Power Transmission,” “Anhui-to-East Power Transmission,” “Xinjiang-to-Outside Power Transmission,” “Shaanxi-to-Outside Power Transmission,” “Mongolia-to-Outside Power Transmission,” and “North-to-South Power Supply.” (Zhao Xinsheng)