Multi-objective optimization of the motor with the novel Halbach permanent magnet array

In order to reduce the weight of the rotor and improve the dynamic performance of the permanent magnet synchronous motor (PMSM), this paper will present two optimization methods for rotor structure with Halbach arrays. In this paper, a trapezoidal Halbach permanent magnet array (THPMA) and an interval Halbach permanent magnet array (IHPMA) is adopted to optimize the torque ripple rate of the PMSM. Based on amounts of parametric finite element analysis (FEA), the Kriging surrogate model of the torque ripple rate (TRR) and torque rotor-weight ratio (TRWR) are built to investigate the effect of multiple parameters on torque performance and dynamic performance in details. The non-dominated sorting genetic algorithm II (NSGA II) is further employed to optimize the proposed PMSM based on the obtained surrogate model. The FEA is carried out to verify that the TRR is significantly reduced and the TRWR is effectively improved, which proves the potential of the proposed structure in optimizing the performances of the PMSM.