This paper presents how to select the proper slot and pole combination (SPC) and reasonable rotor topologies for an interior permanent-magnet (IPM) machine. Firstly, the selection principle of SPC is reported, and some electromagnet performances, incl...
This paper presents how to select the proper slot and pole combination (SPC) and reasonable rotor topologies for an interior permanent-magnet (IPM) machine. Firstly, the selection principle of SPC is reported, and some electromagnet performances, including winding factor, stator space magneto-motive force (MMF) harmonics, radial force harmonics, and cogging torque, are analyzed and compared. Secondly, four PM rotor topologies are designed and discussed, including surface permanent-magnet (SPM), spoke type, V-shape, and multi-layer reluctance (MR) type. Their performances, such as back-EMFs, torque, and ripple and flux-weakening capability, are thoroughly analyzed and compared by the finite-element method (FEM). Finally, a 27-slot and 8-pole V-shape IPM machine is selected and designed optimally, which offers high power/torque density, high efficiency, and less torque ripple. In order to ensure the reliability of its rotor mechanical strength, the equivalent stress and deformation are analyzed by ANASY. Besides, its d-q axis mathematical model is built to verify its performance further. Then experiments on the prototypes are carried out for validation.