Design and Optimization of a Partitioned Stator Hybrid Excited Machine With Inset PM From Perspective of Airgap Field Harmonics

In this article, a novel partitioned stator hybrid excited machine with inset permanent magnet is proposed, which offers reduced flux leakage of permanent magnet and parallel flux paths. Also, the partitioned stator is introduced to alleviate the space conflict between multiple excitation sources. Thus, its torque and flux regulation capability can be improved. In order to understand the hybrid excited principle and improve the electromagnetic performances, the machine is analyzed and optimized from perspective of airgap field harmonics. First, airgap field harmonics produced by field modulation effect of the machine are analyzed and calculated by equivalent airgap model. Then, an optimization method based on airgap field harmonics is proposed and implemented to improve its electromagnetic performances. Finally, the machine design and optimization method are evaluated and verified by both finite element analysis and prototype experiments.