[Objective] Aiming at the problems of designing and tuning the weighting factors of the model predictive torque control (MPTC) of dual three-phase permanent magnet synchronous motor (DTP-PMSM) and the high harmonic currents in the x-y plane

an improved MPTC method with fuzzy unweighted factor based on virtual vectors was proposed. [Methods] Firstly

the tracking errors of torque and flux linkage were constrained by fuzzy dynamic boundary conditions

respectively

and the selection of voltage vectors was carried out under the constraint boundaries. The selected voltage vectors were required to keep the tracking errors of the torque and flux linkage within the boundary conditions

respectively. The two sets of vectors that meet the two boundary conditions were intersected according to set rules to select the optimal vector. Secondly

a set of virtual voltage vectors synthesized from four vectors was introduced as an alternative set of vectors to suppress the harmonic currents of the system. Finally

the improved MPTC proposed in this paper was compared and analyzed with the traditional MPTC

virtual vector-based MPTC and relative error rate cost function-based MPTC through simulation. [Results] The simulation results showed that compared with the traditional MPTC

virtual vector-based MPTC and relative error rate cost function-based MPTC

the total harmonic distortion of phase current of the improved MPTC proposed in this paper was reduced by 87.53%

26.57% and 35.05%

respectively. The root mean square error of flux linkage ripple was reduced by 69.23%

50% and 20%

and the root mean square error of torque ripple was reduced by 6.15%

4.95% and 3.89%

respectively. The regulation time at load start-up was reduced by 15.7%

22.9% and 44.8%

respectively

with smaller steady-state error and faster response. [Conclusion] The control method proposed in this paper not only achieves effective control of torque and flux linkage in DTP-PMSMs

but also eliminates the uncertainty introduced by the weighting factor

improves the dynamic performance of the system

and effectively suppresses the harmonic currents in the x-y plane

which has good feasibility.