Key Technologies and Innovation Prospects of Large-Capacity Voltage Sourced Inverter in the Construction of New Power Systems

the large-capacity SVG based on modular multilevel technology is an important equipment to support the construction of new power systems, which could realize various functions such as active network construction, reactive power compensation, harmonic suppression, impedance remodeling, etc.. In this paper, the basic topological principles of SVG are introduced, and the evolutionary conversion relationship between SVG and modular multilevel converter(MMC) are analyzed. On this basis, the quantitative evaluation formula of AC grid strength supporting by SVG are presented, and advantages of SVG are summarized to ensure the safe and stable operation of the new power system with a high proportion of new energy and power electronic equipments. Then, the key technologies such as the SVG-based multi-source commutation converter technology(SLCC), the active filter, the grid-forming SVG, and the SVG with energy storage ability were analyzed. Finally, the critical SVG development role in constructing new power system and the main research directions are discussed.