Comprehensive Sensitivity Analysis and Multiobjective Optimization Research of Permanent Magnet Flux-Intensifying Motors

In this paper, two permanent magnet flux-intensifying motors are designed and optimized to realize the characteristic of L-d > L-q and the flux-intensifying effect. Compared with the conventional interior permanent magnet motor with the characteristic of L-d < L-q, the advantages of a low irreversible demagnetization risk and a wide speed range can be obtained in the motors. To meet multiple design requirements effectively, a comprehensive sensitivity analysis method is first implemented to evaluate the influence of each design variable on the selected optimized objectives of output torque, reverse saliency ratio, and torque ripple. Second, a sequential nonlinear programming algorithm is used for realizing the multiobjective optimizations of strong-sensitive design variables. Then, the performances of the two optimal motors are analyzed and compared with the initial permanent magnet motor in detail. Finally, two prototype motors are manufactured and tested. Both the simulation and experimental results verify the validity of the new flux-intensifying motors and the optimization method.