Modular multilevel converter control strategy for future DC subsea electric transmission and distribution systems

Future dc subsea electric transmission and distribution system (DC-SETDS) will profit from efficient, robust and small voltage source converter based high voltage transmission dc systems (VSC-HVDC). In this context, the Modular Multilevel Converter (MMC) is an attractive solution since it fulfills such requirements. This work presents a modeling procedure based on state space averaging for the MMC and proposes an MMC currents and voltages control strategy that aims to provide appropriate performance for the MMC VSC-HVDC rectifier in DC-SETDS applications. Simulation results illustrate the achieved performance of the MMC in a given system specification.