Flexible DC transmission system, also known as voltage source converter (VSC), is a new type of DC transmission technology developed in recent years. The system includes DC submarine cables, converter transformers and related accessories. The

Power transmission, interconnection and control of multiple AC grids, and incorporation of different grids, such as island grids, offshore platforms, wind power generation, decentralized small-scale power plants, large-distance power supply, and offshore power supply.

The advantages of submarine DC cables are: high transmission efficiency, low line loss, which is conducive to distance transmission; easy to adjust the current and change the direction of power transmission, high stability; does not produce large short circuit and loop current; has a longer compared with the AC system Lifetime; improve power quality of distribution network.