Improved Model Predictive Control Strategy for Modular Multilevel Converter

For reducing switching frequency and decrease computation of the traditional model predictive control (MPC) for modular multilevel converter, an improved MPC strategy is proposed. The control of AC current, circulating current and capacitor voltages are realized synchronously by building multi-objective functions. Combining with capacitor voltage sorting method, MPC calculation is decreased. The switch frequency was lowered by introducing weighting factors. Capacitor voltage difference among the sub-modules is lessened through the allowable value of capacitor voltage deviation between sub-modules. The simulation results verify its correctness.