Research on Topology and Control Strategy of DR-MMC Cascaded Hybrid HVDC Transmission System for Offshore Wind Power

Establishing a new type of power system with new energy as the mainstay, offshore wind power needs to be greatly flourished. Based on the research background of 2 GW offshore wind power grid connection, the DR-MMC hybrid cascade system is firstly proposed in this paper. Based on reactive power requirements, the feasible operating range of MMC under different capacities was solved. Therefore, the system parameters were optimized. Then designed the corresponding start-up, steady-state and reactive power coordination control strategies for the system. Finally, the electromagnetic transient simulation model of DR-MMC cascaded hybrid HVDC transmission system is built in PSCAD/EMTDC, and the simulation verified the feasibility of the proposed system topology and the effectiveness of the control strategy.