Finite-Set Model Predictive Control for a Hybrid Modular Multilevel Converter in a Microgrid

With the rapid development of power electronic technology, modular multilevel converters (MMCs) are known as one of the applicable and effective typologies of voltage source converters (VSCs). However, the control of the MMCs is complicated and can be challenging due to the use of a large number of submodules. Also, using traditional controlling methods for the MMCs shows slow transient responses during faults. Model predictive control (MPC) has been proposed as a promising alternative to overcome this challenge. The MPC provides MMCs with controlling multiple objectives with a single cost function, improving the dynamic response. In this study, the MMC includes half-bridge and full-bridge submodules, which is refer to as a Hybrid MMC. An electrical vehicle charging station is considered as a source of harmonics used in this study. This paper develops a Hybrid MMC controlled by a discrete-time model predictive control, finite set MPC (FS-MPC), for a hybrid MMC. The result of comparing the FS-MPC performance with a PI controller shows the efficacy of the FS-MPC for harmonic reduction, fast transient responses, and circulating current mitigation.