Magnet shape influence on the performance of AFPMM in a torus configuration

The axial flux permanent magnet machine (AFPMM)is being increasingly demanded for special applications, particularly for transportation systems and concretely for inwheel applications. In this paper the effect of the magnets shape on the AFPMM performance has been analyzed by means of 3DFEM simulations. To this end the air-gap magnetic flux density, the back electromotive force (back-EMF), the cogging torque and the total torque waveforms of the analyzed AFPMMs with different magnets geometries have been studied and compared. The harmonic content of all these variables has been also analyzed. These analyses are carried out to find out the more suitable geometry for in-wheel applications and particularly to minimize the torque ripple of the AFPMM