Grading Model Predictive Control of Control Set Simplified for Single-Phase Three-Level Neutral Point Clamped Cascade Rectifiers

This paper proposes a dual-vector limited set Model Predictive Control (MPC) method for three-level neutral point clamped cascade rectifiers (3LNPC-CR). The method decouples the relationship between three control objectives by constructing a two-dimensional control region, avoids the design of weight factors in multi-objective optimization problems by constructing two value functions, and introduces redundant vectors to allow candidate dual vectors to switch within the control region, thus balancing the neutral point voltage. The selection of dual vectors and the pre-determined control path significantly reduce the number of times the Finite Control Set Model Predictive Control (FCS-MPC) traverses the optimization. Finally, simulation results verify the feasibility of the proposed control method.