The Hainan interconnection system spans the Qiongzhou Strait. The project is constructed in two phases. There are seven 500kV submarine cables in the middle, and a single cable is about 30.5 kilometers long. It is China's first 500kV ultra-high voltage, long-distance, large-capacity submarine power. The construction scale is the largest in Asia and the second in the world.

Laying cables on the seabed to build networking systems is no easy task. The Qiongzhou Strait has a wide sea area, complex seabed geology, high waves and rapid water, with an average water depth of 44 meters and a maximum depth of 110 meters. The builders must solve the two major problems of laying the Qiongzhou Strait submarine cable without any domestic experience, and achieve an unprecedented breakthrough in technology.

After long-term exploration and accumulation, China Southern Power Grid has established an intelligent submarine cable operation and maintenance system, and achieved practical results in the operation and maintenance of submarine cable transmission projects. Professionals in operation and maintenance of submarine cables are also affectionately known as "Southern Network Navy".

The commissioning of the project ended the century-old history of power island in Hainan, and realized the interconnection between the main grid of China Southern Power Grid and Hainan Power Grid.Editor/Ma Xue