An Optimized Rotor Design of Synchronous Reluctance Motor for Improved Torque Characteristics

Permanent Magnet Synchronous Motors (PMSM) are known to be preferred over other motors in electric vehicle (EV) application. However, due to over-dependence of expensive rare-earth magnets in these motors, lookout for alternate motors is on the anvil. In this paper, an optimized rotor design of Synchronous Reluctance Motor (SynRM) that is devoid of rare-earth materials is proposed in order to demonstrate its suitability in the EV category. Firstly, an analytical design method to determine the dimension of the stator and rotor structure of the SynRM is introduced. Without altering the stator design, an optimized design of rotor structure using the unit-less variables is proposed in this paper with the dual aim of maximizing the electromagnetic torque of the SynRM and minimizing torque ripple in it. Finite element analysis (FEA) is used to verify the analytical design and optimization of the rotor structure. The results of the SynRM design and optimization are presented to showcase the effectiveness of the envisaged design methodology.