Performance comparison between switching-flux and IPM machine with rare earth and ferrite PMs

Switching Flux Permanent Magnet machines compared with Interior Permanent Magnet machines are presented to be interesting solutions in terms of torque per volume density, compactness, active material layout and cooling capability. The flux linkage results to be bi-directional and voltage is almost sinusoidal. These machines are then interesting for AC drives and field weakening operation. Employing low cost magnet material must be carefully evaluated despite of the lack of torque capability adopting rare earths permanent magnet can be recovered with cost saving.