State Grid Huai'an Power Supply Company: Independently Completes its First 500kV Equipotential Live-line Work

Recently, State Grid Huai'an Power Supply Company independently carried out its first equipotential live-line work on a 500kV transmission line at Tower 142 of 500kV Yishang Line 5251.

Operators fasten the traction rope to the wire via a drone

Equipotential live-line work, namely, operators directly contact live high-voltage wires to keep their body potential consistent with the wire potential, so as to eliminate defects and conduct maintenance without power cut.

Previously, Xu Gang, a transmission line operations and maintenance technician of this company, found during the peak summer infrared temperature measurement for this line that the temperature of the drainage plate of the tension clamp at Tower 142 reached 49.2℃. Without timely treatment, the overheating would worsen continuously, causing ablation of drainage plates and broken wire strands in mild cases, and even line tripping in severe cases.

Operators eliminate defects at the overheating locations under live-line conditions

To maintain smooth defect elimination, this company carefully formulated dedicated operation plans, refined safety management measures, improved emergency response plans and carried out various drills for operators in advance. During the operation, under the command of the on-site work leader, all staff followed standard operating procedures to fasten the bolts of overheated drainage plates one by one and successfully eliminated the overheating defect.

The successful completion of this 500kV equipotential live-line work has not only eliminated major power grid safety hazards in Huai'an, but also fully verified the professional competence and emergency response capacity of this company’s live-line operation team, which has accumulated valuable practical experience for future work. (Text/Photos by Li Yu and Zhang Jianbiao)