Recently, Gezhouba Shanghai Nanqiao HVDC transmission project is the first ± 500 kV extra High-voltage direct current line in China, which was officially put into operation after undergoing transformation. This transformation marks the transformation of the high-voltage transmission line route from all imports to national production.

The Ge'nan DC transmission project, which was completed and put into operation in 1989, serves as an important channel for external electricity to enter Shanghai. For more than 30 years, the line has continuously supplied clean hydropower from Gezhouba to the Shanghai power grid. In the past 15 years, the average annual electricity transmission has been about 5.5 billion kilowatt hours, providing important energy security for Shanghai's economic takeoff.

At the beginning of the construction of the Ge'nan DC transmission project, China's power industry was still lagging behind, and all types of equipment in the converter station were imported. With the increase of years, equipment such as converter valves are severely aging and unstable in operation. In order to ensure the power supply in East China, the State Grid Corporation of China took half a year to carry out the overall technical transformation of the core equipment of Shanghai Nanqiao Converter Station from full import to national production.

The biggest highlight of this transformation project is the use of the controllable commutation valve technology, which is the world's first and China's fully independent research and development. This is an innovation of the traditional ultra-high voltage DC transmission technology.

The controllable commutation valve  technology, which was first used in this renovation project, is equivalent to accurately introducing fully controlled devices to achieve heart bypass during arterial disturbance, thus completely solving the technical problem of commutation valve failure.

The renovation and safe operation of the Ge'nan HVDC transmission project also indicate that China's original controllable commutation valve  technology has been successfully implemented at the application level, providing a new technical solution for large-scale clean energy access in areas such as East and South China. Editor/Xie Li