The research on steady-state control of flexible DC transmission based on MMC

Modular Multilevel Converter, as a new member of VSC, has been used for DC transmission field for its special modular topology structure. Based on the research of traditional voltage source inverter control mode, MMC mathematical model is derived and it is pointed out that MMC - HVDC can adopt the traditional control strategy of VSC - HVDC, considering that station-level control strategy has direct action on HVDC steady state operation, this paper focus on the design of station-level control strategy, and finally by using PSCAD/EMTDC software to build 9 level model of HVDC based on MMC, and through the simulation results the validity of the station-level control strategy design is verified.