Comparison of operating characteristics of modular multilevel converter under optimized model predictive control strategy and cascaded control strategy

There are such defects as too much states to be predicted, heavy burden of calculated amount and unable to be implemented by existing processors in the model prediction control for modular multilevel converters (MMC). Combining with sub-modules capacitor voltage sorting strategy, an optimized model predictive control (OMPC) strategy is proposed, thus the calculated amount of model predictive control (MPC) algorithm is evidently reduced and it comes true to apply this algorithm in MMC. A simulation and experimental platform for 23-level MMC is constructed and compared with frequently used closed-loop vector control strategy based on cascaded proportion integration (PI) controller, and the comparison results show that the proposed control strategy is of feasibility and superiority.