Experimental Comparison of PM-Assisted Synchronous Reluctance Motors

The aim of this paper is to show the results of various experimental tests carried out on synchronous reluctance (REL) motors with different rotor geometries, as proposed in technical literature. The impact of the assistance of ferrite permanent-magnet (PM) inset in the flux barriers is considered: PM-assisted REL motors are compared with synchronous REL motors, highlighting the main benefits of the former solution. The effect of the rotor skewing and of adopting asymmetric geometries of the flux barriers to reduce the torque ripple is investigated by means of several tests. The impact of the lamination is also considered, as far as the overload capability is concerned. In addition to the experimental tests, a finite-element model is adopted to predict the performance of the motors. The predicted results are compared with the experimental ones in a wide operating range, showing a good agreement.