Design and Performance Comparison of Synchronous Reluctance Motor and Ferrite assisted Synchronous Reluctance Motor for Traction Application

Interior permanent magnet synchronous machines (IPM) employing rare earth magnets are currently used for electric vehicle (EV) application because of their inherent high torque and power density. But high volatility in price and supply of rare earth magnets have forced the automotive industry to search for the alternative electric machine design such as Synchronous Reluctance Motor. This paper compares the performance of Synchronous Reluctance Motor (SynRM) and Ferrite assisted Synchronous Reluctance Motor (Ferrite-SynRM) with Prius2004 IPM for EV application, in terms of electromagnetic performance, weight and material cost. To begin, the sensitivity of some key stator and rotor design variables are performed. Then, with the aid of multi-objective genetic algorithm, optimal geometries of SynRM and Ferrite-SynRM are developed. The predicted results show that the proposed Ferrite-SynRM is suitable for EV application because of its high torque capability, minimum torque ripple, and lower cost.