A Satisfactory Optimization Sequential FCS-MPC Scheme for PMSMs Fed by Three-Level Inverter

To address the challenges associated with medium-voltage (MV) high-power drive systems powered by three-level inverters, including the need for multi-objective optimization to control neutral-point voltage and achieve low switching frequency, as well as the difficulties and complexity of designing weighting factors, this paper proposes a satisfactory optimization sequential FCS-MPC (SO-SMPC) scheme. The current tracking, neutral-point voltage balancing, and switching frequency are assigned high, medium, and low priorities, respectively, and an optimized solution that satisfies all three control objectives is obtained through a multi-layer cost function. Furthermore, the proposed SO-SMPC scheme introduces the deadbeat (DB) control to achieve candidate vector preselection and reduce the computational burden of the enumeration search algorithm. Finally, the effectiveness of the proposed SO-SMPC scheme is experimentally verified on a three-phase permanent magnet synchronous motor (PMSM) drive system powered by a three-level neutral-point clamped (NPC) inverter.