Interpolation-Based Torque Control Strategy for Torque Ripple Reduction in Flux-Concentrated PMSM With Auxiliary Stator

The flux-concentrated permanent magnet synchronous motor (FC-PMSM) with auxiliary stator characterized by its high torque density and efficiency, also encounters the challenge of torque ripple caused by the specific electromagnetic design. To address this issue, a control strategy for torque ripple reduction employing the interpolation method to construct torque response model is introduced. By obtaining an accurate torque response model, the torque ripple is predicted and the optimal current reference is designed. First, the torque characteristics of different positions of the rotor are captured by the finite element method (FEM), and the comprehensive torque response model is established by the cubic spline interpolation method. Subsequently, the maximum torque-per-ampere (MTPA) curve for each rotor position is identified, and the current operating trajectories of the instantaneous MTPA are obtained. Compared with the constant MTPA curve, the instantaneous MTPA curves can effectively characterize the running state at different positions. The simulation results show that the proposed control strategy can reduce the torque ripple by more than 16% in the FC-PMSM with auxiliary stator. Finally, an experimental platform is built to measure the torque response and torque ripple of the FC-PMSM with auxiliary stator. The dynamic and static performances of the FC-PMSM are measured to verify the effectiveness of the proposed strategy.