Chinese workers complete world's first operation on 1,100-kv DC transmission line

HEFEI -- Chinese workers just completed a live-wire operation on the 1,100-kv direct-current transmission line in the city of Lu'an in East China's Anhui province, which is the first-ever case in the world.

The operation came after a drone inspection when a patroller found a pin that should have been fixed on a cable clamp of a tower missing, which could affect the safe operation of the line. The whole operation took less than 50 minutes.

"The line linking Northwest China's Xinjiang Uygur autonomous region and the southern part of Anhui province is the first 1,100-kv DC transmission line in the world, and there is no previous experience on its operation and maintenance," said Wu Weiguo with Anhui Electric Power Transmission and Transformation Co., Ltd.

The west-to-east ultra-high-voltage (UHV) DC power transmission line, stretching 3,324 kilometers long, passes through China's Xinjiang, Gansu, Ningxia, Shaanxi, Henan and Anhui. It can transmit 66 billion kilowatt-hours of electricity to eastern China annually.

UHV is defined as voltage of 1,000 kilovolts or above in alternating current and 800 kilovolts or above in direct current. It can deliver large quantities of power over long distances with less power loss than the more commonly used 500-kilovolt lines.