Generalized Design and Optimization of the Surface-Mounted PMSM With Cost-Effective Magnet Configurations

In this paper, the generalized design and optimization approach is presented for a surface-mounted permanent magnet synchronous motor (SPMSM) with cost-effective magnet configurations. The key design criteria for the proposed SPMSM is the rational configuration of low-cost AlNiCo magnets mounted in the region to avoid demagnetization resulting from the armature reaction, while maintaining the similar output performance to the motor with NdFeB magnets. Based on the main flux analysis, the equivalent magnetic circuit of the proposed SPMSM with cost-effective magnet configurations is established, and then the dimension of two magnets is determined by the comprehensive analysis of working points, configuration angle, and thickness of the magnets. To further improve the performance and reduce the magnet cost, a multi-objective optimization is carried out to optimize the output torque, torque ripple, and torque cost of the proposed SPMSM. The effectiveness of the design and optimization approach is verified by comparing the electromagnetic performance and torque cost with those of the conventional SPMSM with NdFeB magnets. Finally, a prototype of the optimized SPMSM with the cost-effective magnet configurations is manufactured and the motor performance is verified by the experiments.