XJ has comprehensively made breakthroughs in and mastered a complete set of core and key technologies such as the basic theory, product design, manufacturing process, equivalent test and engineering application of ±800kV and below VSC-HVDC converter valves, developed ±200kV-±800kV converter valves, and successively realized the first set of demonstration applications in various scenarios such as Zhoushan Multi-terminal VSC-HVDC Project, Chongqing-Hubei Back-to-Back Interconnection Project, Zhangbei DC Power Grid Project and Wudongde UHV Multi-terminal Hybrid DC Transmission Project.