Analysis and optimization of EMF waveform of a novel axial field flux-switching permanent magnet machine

Axial field flux-switching permanent magnet motor is a novel PM machine of doubly-salient structure, with magnets and concentrated windings in the stator. This novel machine is suitable for electric vehicle because of its short axial length, high power and torque density. A typical 3-phase 12/10-pole AFFSPM motor is designed and prototyped. In order to gain sinusoidal back-EMF waveform, the influence of the design parameters, such as the stator tooth width, the magnet size, the stator yoke thickness, the stator tooth shape, the rotor pole width, and the rotor pole shape, on the back-EMF is investigated based on 3D FE analysis. It shows that the harmonics of back-EMF can be significantly reduced and the waveform of the back-EMF is sinusoidal by optimizing the stator tooth shape, the rotor pole width and shape. The experiments are conducted and the results are in agreement with the theoretical analysis.