Zero-Vector-Free MPC with Virtual Vector Synthesis for CMV Suppression in Electric Propulsion Systems

This study proposes a novel finite control set model predictive control strategy (FCS-MPC) to suppress common-mode voltage (CMV) in electric propulsion systems while maintaining current quality. The key innovation is a virtual multi-vector synthesis method that eliminates zero-voltage vectors by adaptively generating small and medium vectors based on the modulation index and voltage sector. Unlike conventional CMV-reduction methods that compromise current quality or rely on fixed switching states, the proposed method enhances voltage resolution without relying on zero vectors. Simulation results demonstrate that, compared to conventional MPC, the proposed method reduces the CMV from approximately 100 V to 33 V—a 66.7% reduction. In terms of current quality, it achieves a 22.0% reduction in total harmonic distortion (THD) compared to the conventional reduced-CMV MPC method under low modulation conditions, while avoiding its excessive switching frequency. Experimental validation confirms both stable waveform generation and robust CMV suppression, while the proposed MPC reduces DSP execution time from 30.88 μs to 22.71 μs, thereby increasing computational availability to 77.3% and enabling real-time implementation on low-cost hardware. These results confirm the practicality of the proposed controller for real-time marine propulsion systems requiring both electromagnetic compatibility and high current quality.