In 2018, the Zhangbei Flexible Direct Current Demonstration Project started construction

China Energy Storage Network News: China's clean energy development focuses on the western and northern regions, mostly at the end of the power grid, or even in areas without power grids. The AC power grid is difficult to support the safe and stable operation of large-scale conventional DC. To solve this problem, State Grid Corporation of China is actively exploring.

On February 28, the Zhangbei Renewable Energy Flexible DC Grid Experimental Demonstration Project was launched in Beijing. This project is the world's first DC grid project with network characteristics, and also the world's highest voltage level and largest transmission capacity flexible DC project. It is an important milestone in the history of power grid technology in my country and even the world.

Flexible DC has the characteristics of good controllability and flexible operation mode, and has significant advantages in new energy grid connection, weak system interconnection, urban power supply, etc. The DC grid built based on flexible DC has better flexibility and reliability. It can directly connect wind power, photovoltaic power, pumped storage and load center to form an energy Internet with flexible and complementary energy in various forms, realize multi-power supply, multi-point power receiving and new energy island access, and can effectively smooth out the intermittent and volatile nature of new energy; by giving full play to the network advantages of DC grid such as online isolation of local faults and multi-route redundancy, it can achieve rapid removal and isolation of faults, greatly improving the reliability of power transmission. Zhangbei Flexible DC Project is a major project for the company to thoroughly implement the central decision-making and deployment and serve the clean and low-carbon development of energy.

The rated voltage of the project is ±500 kV, and a 666 km ±500 kV DC transmission line will be built. Four converter stations will be newly built in Zhangbei, Kangbao, Fengning and Beijing, with a total converter capacity of 9 million kilowatts. The total investment of the project is 12.5 billion yuan. It was approved by the state in December 2017, and it is expected to be completed and put into operation by the end of 2019 and in the first half of 2020. The project has been included in the national "13th Five-Year Plan for Power Development (2016-2020)" and "Energy Technology Revolution Innovation Action Plan (2016-2030)", and has been recommended as a major landmark project of "Made in China 2025" in 2018.