Three-Vector-Based Model Predictive Torque Control for Dual Three-Phase PMSM With Torque and Flux Ripples Reduction

The conventional model predictive torque control (MPTC) used for dual three-phase permanent magnet synchronous motors (DTP-PMSMs) faces several challenges, such as significant computational burden, large current harmonics, and large torque and flux ripples due to the application of imprecise voltage vectors. To address these issues, a novel three-vector-based MPTC strategy was introduced in this article for DTP-PMSMs. First, virtual vectors were adopted to reduce the current harmonic components. Second, four candidate vector groups were determined based on torque deviation and flux position. Each candidate vector group comprised two virtual vectors and one zero vector, which enabled the precise control of torque and flux through the duty-ratio modulation strategy. Third, the switching sequence was optimized to facilitate implementation in digital controllers. Then, a cost function was defined to evaluate the average torque and flux ripples of each candidate vector group in a sampling period, and the one with the minimum cost function was applied in the next sampling period. This approach effectively reduced the current harmonics, torque ripple, and flux ripple while avoiding large computational burden. Finally, experiments were conducted to demonstrate the effectiveness of the proposed method.