Performance Evaluation of a Permanent Magnet Brushless DC Machine With Auxiliary Stator Slots

This article investigates the impact of stator auxiliary slots on the performance and loss distributions of a permanent magnet brushless DC (PMBLDC) machine. Multiple designs of the machine prototype with stator auxiliary slots placed at different positions are investigated in-depth. Firstly, the influence of stator auxiliary slots on the PMBLDC machine air gap magnetic flux density is investigated by considering different machine design cases. Next, the output torque, cogging torque, back-EMF, and torque ripple response are analyzed and compared for the different machine design cases. The loss distributions for the machine design with auxiliary slots are also extensively researched. Lastly, an optimization analysis is conducted by investigating the impact of stator auxiliary slot dimensions, numbers, and position on the machine performance to obtain an optimized design solution for the PMBLDC machine.