Electromagnetic Performance Analysis and Multiobjective Optimal Design of a Novel Magnet-Shifted PM Motor for Reducing Torque Ripple

In the electromagnetic design stage of PM motors, the consideration of reducing torque ripple is as important as the improvement of motor efficiency. In this article, the electromagnetic performance of the magnet-shifted surface-mounted PM motor is analyzed and calculated in detail. The Maxwell tensor method is used to explain the mechanism of mitigating cogging torque, and it will obtain the optimal magnet-shifted angle more quickly than Finite element parameterization. According to the change rule of winding flux linkage, the winding factor of the proposed motor is calculated, which describes the principle of harmonic generation fundamentally. The magnetic field is affected by many factors and the demagnetization curve of motor materials is nonlinear, so a multiobjective optimization strategy based on the genetic algorithm and the finite element calculation is selected to acquire the best parameters.