On March 1, 2023, amidst the sound of roaring machines, the Sichuan-Chongqing 1,000-kilovolt UHV AC Project (Chongqing Section) began a basic process pilot in Xiaodu Town, Tongnan District, Chongqing. This marks the first UHV project in Chongqing to enter the comprehensive construction period.

The Sichuan-Chongqing 1,000-kilovolt UHV AC project is a key power transmission project specified in the national "14th Five-Year Plan" for Electric Power Development, and it is included in the "2023 List of Major Projects for the Joint Construction of the Twin-City Economic Circle in the Chongqing Region".

The entire project will build four UHV substations in Sichuan Ganzi, Tianfu South, Chengdu East and Chongqing Tongliang, with a transformation capacity of 24 million KVA, and a new double-circuit UHV line of about 657 kilometers, with a total investment of 28.6 billion yuan. After the completion of the project, the voltage level of the main grid of the Southwest Power Grid will be raised from 500 kV to 1,000 kV, which can effectively undertake the export of clean power such as hydropower in Ganzi and Aba areas in western Sichuan, and ensure the power consumption needs of Chengdu-Chongqing load centers.

After entering Chongqing, the routes of the Sichuan-Chongqing 1000 kV UHV AC project are dominated by hills and mountains, accounting for 56.9% and 35.2% respectively. The construction faces many construction challenges, especially in the construction stage of large earth and rock volume foundations. It is difficult to control.

"We actively use technology to 'clear the way' and use intelligence to 'break the problem'." Jiang Bin, the on-site project manager of State Grid Chongqing Construction Company, said that during the construction of the project, all foundation excavations were made with rotary excavators. When pouring concrete, All cast-in-situ piles are used for pouring, which avoids the safety risk of personnel going into the pit, and Chongqing Electric Power Engineering also realizes for the first time that operators do not go down the pit during the whole process of foundation construction.

How to ensure the quality of concrete pouring? Jiang Bin revealed that the advanced "smart IoT sensing system" is used in all operations, which can collect, store, and transmit timely data on the concrete pouring stress, temperature, and inclination angle of the tower base, and complete automatic reporting. Once a problem is found, it can be Deal with it immediately.

At the same time, the steel towers of this project are all made of steel pipe towers, with an average single-base weight of 215 tons, setting a record for the heaviest average single-base iron tower in Chongqing transmission line projects. The line foundation, tower assembly, and wiring are all mechanized construction, which is the first fully mechanized operation in Chongqing.

The relevant person in charge of the State Grid Chongqing Electric Power Company said that the Sichuan-Chongqing 1000 kV UHV AC project is the first UHV project in Chongqing. After completion, it will greatly accelerate the integration process of the Sichuan-Chongqing power grid, improve the overall power supply capacity of the Southwest Power Grid and The reliability of operation provides more sufficient and reliable power guarantee for the construction of the Chengdu-Chongqing economic circle. Editor/Xu Shengpeng