Influence of rotor flux-barrier geometry on torque and torque ripple of permanent-magnet-assisted synchronous reluctance motors

The rotor design has a large effect on the performance of Permanent-Magnet-Assisted Synchronous Reluctance Motors (PMaSynRMs). An optimized rotor geometry is necessary in order to obtain higher motor torque with minimum torque ripple. This paper investigates the influence of the flux-barrier design which is the most important rotor geometry parameter regarding the torque and torque ripple of PMaSynRMs. The flux-barrier parameters are angle, width, and position, as well as the length. Starting from the optimized rotor of a SynRM without magnets, a PMaSynRM is created by inserting permanent-magnets inside the center of the flux-barriers. For a prototype SynRM, experimental results have been obtained to validate the FEM results and to validate the strategy for choosing the rotor parameters.