Selection of Optimal Rotor Geometry for PM-Assisted Synchronous Reluctance Motor used in EV Applications

Electric vehicular applications require electric motor design with high torque density, high efficiency and moderate power factor and moderate cost. PMSM is widely used and fulfill all the requirements for best candidate to be employed in EVs. Due to high requirement of PMs in PMSM, high cost and monopoly of PM material availability, researchers and EV manufacturing industries are finding the new alternative. In PM assisted Synchronous Reluctance Motor (PMASynRM), less number of PMs are required in flux barriers. This will mainly improve the PF of PMASynRM against SynRM and also add the PM torque component with reluctance torque component. Here two different number of rotor poles are selected. First by fixing the four rotor poles, number of flux barriers is varied from two to four and performance of motor is investigated through FEA. Then number of rotor poles increased from four to eight with flux barriers varied from two to four and performance of motor is investigated through FEA. The purpose of comparison of all six geometries of PMASynRM for all possible performance parameters is to develop the optimal design with best suitable combination of rotor poles and number of flux barriers. Although selection of geometry is also depend on manufacturability and performance requirements for EVs. The prototype for the PMASynRM is under developing stage to validate the investigation of performance parameters.