Investigation of Stator Spoke-Type Permanent Magnet Machine Considering Different Slot and Pole Combinations

This paper presents the slot design procedure and performance evaluation of a stator spoke-type (SSTPM) machine by combing the distinct advantages of simple rotor, good thermal management in stator permanent magnet (PM) machine, and flux-concentrating effect in spoke-type structure. In addition, since the PMs are located between the adjacent stator tooth tips, the parallel magnetic circuit relation between PM and armature reaction fields permits excellent demagnetization withstand capability of magnets. Firstly, the machine topology and operating principle are introduced, respectively. Afterwards, the feasible stator and rotor pole combinations for the proposed SSTPM machine are discussed. The electromagnetic performance of SSTPM machines with selected slot/pole combinations are evaluated and compared by using finite-element (FE) method. Finally, a 12/14-stator/rotor pole SSTPM machine prototype is manufactured and tested to verify the FE analysis.