Research on Demonstration Project of Zhangbei Flexible DC Grid

With the successful commissioning of a number of domestic flexible DC projects, the flexible DC technology has been mature, and the DC grids based on flexible DC will be the future development direction. As a supporting clean energy project for the 2022 Olympic Winter Games, State Grid Corporation has built the world's first four-terminal flexible DC grid project (Zhangbei Project) in Zhangbei, with a total converter station capacity of 9 million. As the first DC grid demonstration project, this article focuses on the project overview, DC grid design, development of key equipment, and safety and stability control methods after grid connection, which provides a wealth of practical experiences for the design and application of subsequent DC grid projects, also promotes the development of flexible DC technology in China and even in the world.