On July 29, the world's first UHV flexible DC project, the Gansu-Zhejiang ±800 kV UHV DC transmission project, started construction. This is the world's first cross-regional UHV DC transmission project that uses flexible DC transmission technology at both the sending and receiving ends. After the project is completed, it will be able to transport more than 36 billion kilowatt-hours of electricity from Gansu to Zhejiang every year, more than half of which is new energy electricity.

The East China Institute, the Central South Institute, the Northwest Institute, the Shanxi Institute, the Jiangsu Institute, the Zhejiang Institute, the Anhui Institute, the Shaanxi Institute, the Gansu Institute, and the Xinjiang Institute affiliated to CEEC are responsible for the relevant surveys of the Gansu-Zhejiang ±800 kV UHV DC project Design work.

The project starts from the sending end converter station in Minqin County, Wuwei, Gansu Province, and ends at the receiving end converter station in Shangyu District, Shaoxing City, Zhejiang Province. The total length of the line is approximately 2,370 kilometers, passing through six provinces: Gansu, Ningxia, Shaanxi, Henan, Anhui, and Zhejiang. After the project is completed and put into operation, it will promote Zhejiang to form a "one ring and four direct" UHV backbone grid, and implement a new energy supply model that features multi-energy complementation, intensive development, large-scale transmission, and large-scale consumption.

The Northwest Institute is responsible for a total of 3 feasibility studies and survey and design projects including the primary feasibility study of the transmission end converter station system of the Gansu-Zhejiang UHV DC project, the transmission end converter station package A, and the line package 2 (including the Yellow River crossing). Line package 2 starts from Jingtai County, Gansu Province and ends at the border of Gansu and Ningxia provinces. The length of the line is 170 kilometers (including the 2.5 kilometers long stretch section of the Yellow River).

Central South Institute is responsible for Package B of the feasibility study and survey and design project of the transmission end converter station of the Gansu-Zhejiang UHV DC project. The project's transmission end converter station is located in Wuwei City, Gansu Province. It adopts a fully flexible DC solution with a voltage level of 800 kV and a transmission capacity of 8 million kilowatts.

The Gansu Institute is responsible for the integrated survey and design work of the Gansu-Zhejiang UHV DC project (Package 1) bid section. The DC line in this packaged section starts from Gansu Shuenduan Converter Station and ends at the boundary between Wuwei Gulang County and Baiyin Jingtai County. The line length is about 161 kilometers. It also includes the supporting grounding pole line of the converter station, which is about 87 kilometers in length. km.

East China Institute is responsible for the primary feasibility study package of the Gansu-Zhejiang UHV DC project package 4 receiving end converter station system, package 6 receiving end converter station B package and package 1 feasibility study of the Gansu-Zhejiang UHV DC project package + submarine cable crossing the Yangtze River plan section and survey and design work.

The Shaanxi Institute is responsible for the feasibility study and survey design package of the Gansu-Zhejiang UHV DC project line for 6 bid sections. The line starts from Beiyuan Town, Baishui County, Weinan City, Shaanxi Province, and ends at Sanguanmiao Village, Huazhou District, Weinan City, Shaanxi Province, passing through Shaanxi Province Baishui County, Pucheng County, Dali County and Huazhou District of Weinan City in the province, with a path length of 165 kilometers.

The Xinjiang Institute is responsible for the Gansu-Zhejiang UHV DC project line feasibility study and survey design package 7 (Huazhou District, Luonan County boundary-Shaanxi and Henan Province boundary section). The line starts from the boundary of Huazhou District and Luonan County, Shangluo City, Shaanxi Province, and ends at the boundary of Shaanxi and Henan Provinces. The route length of this bidding section is 156 kilometers.

Anhui Institute is responsible for the Gansu-Zhejiang UHV DC project feasibility study and survey design package 11. The route length of Bao 11 line is about 188 kilometers, starting from the border of Henan and Anhui provinces and ending at the north side of Luobu Township, Lujiang County, Hefei City.

The Shanxi Institute is responsible for the feasibility study and survey design package 13 of the Gansu-Zhejiang UHV DC project. The length of the Bao 13 line project is 134 kilometers, and the project locations are Nanling County, Wuhu City, Anhui Province, Xuanzhou District, and Ningguo City, Xuancheng City.

Jiangsu Institute is responsible for the Gansu-Zhejiang UHV DC project line feasibility study and survey and design package 15. The Bao 15 line is mainly located in Hangzhou City, Zhejiang Province, with a DC line length of 98 kilometers and a grounding pole line length of 203 kilometers. 

The Zhejiang Institute is responsible for package A of the receiving end converter station of the Gansu-Zhejiang UHV DC project, as well as the feasibility study and survey design of the line section from the Anhui-Zhejiang border to Zhuji City. The DC part of the receiving end converter station adopts a flexible-direct solution, and the voltage level 800 kV, with a transmission capacity of 8 million kilowatts. It is the world's first "double 800" flexible-to-DC converter station.Editor/Jiang Mingyue