On October 31, in Haishiwan Town, Honggu District, Lanzhou City, Gansu Province, live working professionals from State Grid Gansu Ultra-High Voltage Company used the"flying man" construction method to perform live installation of the split pin on the connecting bolt of the middle-phase conductor at Tower No146 of the 750 kV Guowu II Transmission Line. This marked the full entry of live working on ultra-high and extra-high voltage power grids into the era of mechanization and intelligence.

Live working on the phase-to-phase of 750-kilovolt double-circuit lines on the same tower has problems such as a complex electric field environment, limited working space, and high technical requirements.Technical personnel innovated the operation method. It took two years of simulation, repeated verification, and data collection to obtain key data, providing technical and data support for the nationwide implementation of this type of live-line work. This filled the technical gap in live-line work on the middle and upper phases of 750 kV double-circuit lines on the same tower, effectively improving the efficiency of new energy outbound transmission from Gansu and Qinghai and enhancing inter-provincial complementary and mutual assistance capabilities.

State Grid Gansu Ultra High Voltage Company completed the 3D scanning of towers and path planning in advance using laser point cloud technology. During the operation, a drone accurately hung the insulating lifting rope on the lightning conductor to create a safe lifting passage.The equipotential operation personnel wear special 750-kilovolt shielding suits and take the integrated safety auxiliary fixed seat. They can be smoothly lifted to the operation point nearly 60 meters above the ground with one key start from the ground. There is no need to climb the tower or transfer on the tower during the whole process, and the process of entering the electric field can be completed in just a few minutes. 

As of now, there are 33 750-kilovolt double-circuit lines on the same tower in Gansu Province, with a total length of 2,160 kilometers. The successful implementation of the"Flying Man" construction method for live working on the middle phase of the 750-kilovolt double-circuit line on the same tower will provide data and technical support for conducting similar live-line operations in the northwest region. It ensures the safe and stable operation of the 750-kilovolt main grid in the northwest and further enhances the efficiency of new energy transmission from Gansu and Qinghai provinces, as well as inter-provincial complementary and mutual support capabilities.