Effect of Magnets and Diamagnetic Material on Performance of SynRM with Novel Rotor Structure

Abstract

This paper presents a novel rotor structure for two pole synchronous reluctance machine(SynRM) for Electric vehicle application. Performance of the machine depends on direct and quadrature axis inductances. The ratio of these inductances, saliency ratio, affect the torque density and power factor. Therefore, evolution of the rotor structure is presented to achieve high saliency ratio. So, to improve machine performance, ferrite magnets are introduced in the rotor such that polarity is along the maximum reluctance path of the rotor. For further increment of the saliency ratio, diamagnetic material is placed between the bridges to oppose quadrature axis flux and to reduce leakage flux. For validation, SynRM models, with and without ferrite magnets and diamagnetic material, are defined on FEA based ANSYS Maxwell platform to observe magnetic flux distribution. Also, saliency ratio for all the three are compared. Finally, comparisons of developed torque is presented for further verification.