Baihetan on the mountain - Jiangsu ± 800 kV UHVDC transmission project construction site. Photo by Tan Xieyang
State Grid Sichuan Electric Power Transmission and Substation Construction Co., Ltd. revealed on the 19th that the Baihetan-Jiangsu ± 800 kV UHVDC transmission line project located in Shaluo Village, Meigu County, Liangshan Prefecture, Sichuan Province, successfully crossed the 800 kV UHV line of the Jinping-Southern jiangsu ± that has been built. This is the first time in China to carry out UHV across UHV discharge line construction operations in high-altitude heavy ice areas.
Baihetan - Jiangsu ± 800 kV UHVDC transmission line project is a strategic key project of "West-to-East Power Transmission", which is a major clean energy project to promote national energy structure adjustment and energy conservation and emission reduction, the project starts from Butuo County, Liangshan Prefecture, Sichuan Province, and ends in Changshu City, Suzhou, Jiangsu Province, passing through 5 provinces (cities) of Sichuan, Chongqing, Hubei, Anhui and Jiangsu, with a total length of 2087 kilometers and 2 new converter stations. With a total investment of RMB 30.7 billion, the project was approved by the National Development and Reform Commission in November 2020 and is scheduled to be completed and put into operation by the end of June 2022.
Baihetan- Jiangsu ± 800 kV UHVDC transmission project Chuan 1 bid release line construction site. Photo by Tan Xieyang
During the construction period, the temperature in the hinterland of Daliang Mountain was as low as -10 °C, and there were frequent winds and thick fog, and the ground was covered with snow and clouds in the air. The thickness of the wire overlay in the heavy ice area can reach up to 50 mm when the wire is frozen, which is easy to cause difficulties in the installation of tight attachments, and the tensioning machinery and equipment required for the wire display is seriously reduced, affecting the safety of high-altitude work construction. In order to cooperate with the line operation, the construction party overcame difficulties and made preparations in advance for the equipment to enter and arrange, comb the fittings required for tight attachments, and the display of the guide rope. In the cold weather, the staff will first "bake" the ice when working on the tight line, and then tighten the tool. At the same time, increase the allocation of cold-proof work clothes and personnel input, and implement the rotation system for high-altitude work to avoid long-term low-temperature high-altitude work. "The implementation of the crossing in the heavy ice area of more than 2,600 meters is the first time in China." Wu Jianming, secretary of the party branch of the 800 kV UHVDC Transmission Line Project Department of Baihetan-Jiangsu ±, said that the 1 lot of the line Needs to cross the 800 kV UHVDC transmission line section of the Jinping-Jiangsu ±, with a total length of about 5.1 kilometers, involving 11 bases of iron towers.
Power workers are installing spacer rods at high altitudes. Photo by Tan Xieyang
It is understood that in addition to the ultra-high voltage lines running across the operation, the Sichuan 1 lot of the project will also cross 8 500 kV lines, 59 220 kV and 110 kV lines, and 22 highways, with high construction technology requirements and large workload. (Liu Zhongjun, Tan Xieyang) China's first UHV cross-UHV release line construction operation in high-altitude heavy ice areas - China News Network