Design and Performance Optimization of Novel Flux-Concentrating Spoke-Type IPM Machine

This paper introduces a novel spoke-type interior permanent magnet (IPM) machine featuring a flux-concentrating rotor. Its primary objectives are to increase the utilization of PM material and decrease leakage flux. The evolution of the proposed flux-concentrating PM from the spoke-type PM is presented, which demonstrates a higher PM utilization ratio on torque characteristics. To achieve a high-performance design, a multi-objective genetic algorithm (MOGA) is employed for design optimization. This optimization process focuses on maximizing PM material utilization while minimizing torque ripple. The optimized machine configuration is designed to reduce copper loss and enhance efficiency by reducing current density while maintaining a similar average torque to that of the spoke-type machine. The paper utilizes finite element analysis (FEA) to compare the electromagnetic characteristics of the two machines. The results show that the proposed structure improves efficiency by 1.2% and reduces PM volume by approximately 4% in comparison to the spoke-type machine.