Cooperative Strategy of Active Energy Control and AC Energy Dissipation Device in Offshore Wind Power MMC-HVDC System

Aiming at the problems of poor engineering economy and energy waste in offshore wind power flexible direct grid connection system using DC energy consuming devices, this paper presented an active energy control technique for cooperating AC energy dissipation devices. Firstly, the feasibility of active energy control method was verified quantitatively by computing the system's energy margin. Subsequently, an AC/DC current dual control of MMC was provided, and the capacitor energy controllers of the converter were constructed. Further considering the operating of AC energy dissipation devices, a converter energy-AC voltage controller was proposed. On this basis, a cooperative control for active energy control and AC energy dissipation devices was designed. Finally, a simulation model of a typical offshore wind power MMC-HVDC integration system was built in the PSCAD/EMTDC, and the AC faults of different fault types were simulated to verify the effectiveness of the cooperative strategy of active energy control and AC energy dissipation devices. © 2022 Chin. Soc. for Elec. Eng.