Summary
The application of power electronics is an important trend of power system transformation. This paper introduces the world's first flexible interconnection in 220‐kV urban power grid for the first time. This paper presents the key technologies for this project. Firstly, this paper introduces the concept of flexible interconnection, in which the flexible loop operation mode is proposed. Then, this paper introduces the pilot project of partition flexible interconnection in Beijing, China. The project is to build a new flexible DC interconnection based on back‐to‐back modular multilevel converter technology between 2 subtransmission areas in Beijing power supply grid, in order to enhance stability and security. Finally, the project is comprehensively evaluated based on real project data, in which transient voltage stability, static voltage security, total supply capability, short‐circuit current, and reliability are analyzed. The results have shown the effectiveness of the proposed flexible interconnection in large‐scale urban power grid. This project demonstrates a promising application of advanced power electronics in urban power grid.