Model Predictive Current Control for Dual Three-Phase Permanent Magnet Synchronous Motor with Common-Mode Voltage Suppression

Model predictive current control (MPCC) is recognized to be a promising technology for multi-phase drive systems. Particularly when applied to dual three-phase permanent magnet synchronous motors (DT-PMSM), certain factors such as common-mode voltage (CMV), harmonic current and calculation burden need to be taken into account. Additionally, adjusting the weighting factor in the cost function poses a challenge due to the lack of a theoretical basis. Addressing these challenges, this paper proposes a MPCC method for DT-PMSM with CMV suppression. In this proposed method, the virtual voltage vectors (V3s) and equivalent zero V3s are synthesized using large voltage vectors that have small CMVs. Notably, the average voltage of V3s and equivalent zero V3s in the x-y subspace is zero. Consequently, the elimination of the weighting factor of the harmonic current term in the cost function becomes achievable. Furthermore, a method for optimal voltage vector selection is introduced, simplifying the process of candidate voltage vectors and circumventing the traversal prediction calculation process. The proposed method can effectively reduce the harmonic current, limit the peak-to-peak value of the CMV to 1/3 of the inverter DC bus voltage, and relieve the calculation burden. The effectiveness of the proposed method is verified by comparison with existing traditional MPCC methods.