Huadian participated in the successful completion of the 1000kVGIL AC withstand voltage, breakdown location and partial discharge testing test projects for the Sutong Pipe Gallery Project. The Sutong UHV GIL pipe gallery project is the first in the world. The ability of Huadian to participate in such engineering projects further verified the technical level of Huadian's UHV test and on-site organization capabilities, and expanded Huadian's brand influence. After 21 days of the whole project, Huadian invested a total of 41 people to fight continuously. During the project, various difficulties were overcome and the task was finally completed successfully. It has been well received by experts from the UHV Department of State Grid and Jiangsu Electric Power Research Institute.