CSG Yunnan Power Transmission and Transformation Company Successfully Conducted Live Working on 500kV Transmission Lines at an Altitude of 3,900 Meters for the First Time

Diqing - From October 27 to November 15, engineers from the Diqing workstation eliminated current and potential defects in six 500 kV transmission lines of the main grid in Diqing.
Among them was Tower N78 of Jiantaijia 500kV Transmission Line, located in Shangri-La, Diqing, with an operating height of 3,900 meters above sea level. It was the first time in China that engineers braved these dangerous heights and brutal conditions to carry out live line working of 500 kV transmission lines at such a high altitude.
During the 20-day live line working, Diqing workstation engineers worked under a tight schedule and completed arduous physical challenges. Engineers eliminated defects for nearly 100 transmission lines in 30 missions and reduced interruption time by 184 hours, which is equivalent to increasing power supply by approximately 50 million kWh.

Before climbing the tower, operators carefully check their conductive suits for live line working. After entering 500 kV strong electric fields, each suit is the final level of personal protection they can count on to for their safety.

The Diqing workstation is staffed with seasoned managers and talented engineers who are responsible for the operation and maintenance of all six 500 kV transmission lines at the Diqing Tibetan Autonomous Prefecture. With a total length of 403 km and at an average altitude of more than 3,000 m, these transmission lines are an important part of the power grid in Diqing and Yunnan at large and shoulder important tasks such as sending power through cascade power stations upstream of Lancang River as part of the West-East Electricity Transfer Project.
By eliminating defects, Diqing workstation engineers have provided a strong impetus for safe and stable power transmission and distribution throughout Diqing and the main channels of the West-East Electricity Transfer Project. This work then ensures that the power grid electrical supplies meets the needs of social and economic development and people's livelihood in this winter and next spring 2022.

Operators replace fiber optic connectors for Jiantaijia 500kV Transmission Lines at the summit of Tower N47.

Due to severe weather conditions and natural environment of the snow-covered Tibetan plateau, transmission lines are highly susceptible to defects and safety hazards such as insulator self-explosion and the rapid aging of metallic tools, which require timely defect elimination.
In recent years, live line working has been increasingly adopted by Diqing workstation engineers to eliminate defects in transmission lines.
Du Qingtao, Head of the Workstation commented on the advantages of this method, "traditionally, we need to shut down the whole line to eliminate defects. However, live line working can be carried out without interruption. It is the most effective method to shorten interruption duration.”

Operators climb the tower for live line working.

The Diqing workstation has been exerting efforts to reduce interruption duration and improve power supply capabilities since it first carried out live line working dating back two years to Year 2019.
Based on traditional modes, Company engineers had to overcome numerous challenges during live line work on 500 kV transmission lines at a high altitude, which includes demanding safety protection requirements, high risk for operators, and high insulation performance requirements for instruments. Workstation senior managers explored and accumulated technical experience for their engineer staff when working on live ultrahigh tension power lines in high-altitude areas and summarized efficient and practical operation methods.
All of the 20 inspectors at the Diqing workstation have obtained qualification certificates for carrying out live line working and earned superb technical skills during this long-term practical experience.