The first section of the Panxi UHV AC project in Sichuan was successfully completed

China News Service, Chengdu, September 22 (Liu Zhongjun, Gao Hengrui, Xie Chunyan) State Grid Sichuan Electric Power Company announced on the 22nd that as the last phase conductor plate arrived at the predetermined position, the first section of the Panxi UHV AC project in Sichuan was successfully completed, and safely crossed the ±800 kV gold to the Hubei DC transmission line and two 500 kV transmission lines, laying the foundation for the follow-up progress of the project.

The Panxi UHV AC project will start construction at the end of March 2026. Two new 1,000 kV substations will be built in Panxi and South Sichuan. The lines will pass through the three cities (prefectures) of Liangshan, Yibin and Leshan. 22 new iron towers were built in the section where the laying-out work was completed this time, and the total length of the line is about 7.3 kilometers. This section spans densely and has many high and heavy towers. The maximum weight of a single-base tower reaches 518.5 tons and the maximum tower height is 160.8 meters. The construction tasks are heavy and the construction schedule is tight. "The construction of UHV lines is usually carried out in sections, and the crossing construction must be carried out when the existing lines are not energized." Yang Yi, executive deputy manager of the project department of the owner of the eastern section of the Panxi UHV AC project line project, said that it is currently the autumn maintenance window period of the power grid, and all the lines spanned by the project are not energized.

In order to ensure the smooth progress of the project, State Grid Sichuan Electric Power Company planned and planned operations in advance. The construction team promotes mechanized tower assembly technology, and adopts the "crane + rocker arm holding pole" combined construction mode for ultra-high-speed towers above 120 meters to improve the stability and construction efficiency of high tower assembly.

In the laying-out process, four wiring sections were simultaneously deployed on site and 40 supporting tensioning equipment were invested. The traditional serial construction was changed to parallel and synchronous construction, which greatly reduced the overall construction time. "We classified the densely crossed lines in the 11th bidding section as 'early wiring sections' and 'took them out' for early construction to complete the most critical crossings within the limited construction period." Yang Yi said.

The Panxi UHV AC project is expected to be completed in 2028, with a maximum annual power transmission of approximately 18.2 billion kilowatt-hours, equivalent to replacing approximately 5.88 million tons of standard coal and reducing carbon dioxide emissions by approximately 14.46 million tons.

After the completion of the project, the transmission capacity of Panxi clean energy to the Chengdu Plain and southern Sichuan load centers will be enhanced. By then, a "three transmissions and three receptions" grid layout will be formed between the three clean energy bases of Garze, Aba and Panxi and the three load centers of Chengdu Plain, southern Sichuan and northern Sichuan. The safety and stability level and power supply carrying capacity of Sichuan's main grid will also be further improved.