A Model Predictive Control Strategy for the Cascaded H-Bridge Multilevel Rectifier Based on Enumeration

In this paper model predictive control (MPC) is adapted for the cascaded H-bridge (CHB) multilevel rectifier. By directly manipulating the switches, the proposed control scheme aims to keep the input current in phase with the supply voltage, and to achieve independent regulation of the H-bridge cells. Furthermore, since all the possible switching combinations are taken into account, the controller exhibits favorable performance not only under nominal conditions, but also under asymmetrical voltage potentials and unbalanced loads. Finally, and in order to ensure robustness, a short horizon is employed; in that way the required computing remains reasonable, making it possible to implement the algorithm in a real-time system. Experimental results are presented in order to demonstrate the performance of the proposed approach.