Model predictive control of a modular multilevel converter with a reduced number of states

The modular multilevel converter (MMC) has been a subject of great interest for power electronics researchers, especially in HVDC applications. Also, due to the high number of levels commonly utilized with this converter topology, studies have been conducted to simplify its control algorithm. This paper proposes to use a model predictive control (MPC) strategy which considers a reduced number of states, to regulate both AC-side currents and circulating currents. Also a simplified algorithm is used to implement the task of maintaining the submodules' capacitor voltages regulated. These control strategies are applied to a nine-level MMC connected to a medium voltage distribution grid. Its performance is analyzed based on simulation results conducted in the environment of circuit simulations PSIM.