Reduced rib synchronous reluctance motor for traction applications

Abstract

This paper proposes a variable width reduced rib rotor structure for Synchronous Reluctance (SynRel) Motor. In convention supporting iron ribs are introduced in transversally laminated anisotropic (TLA) type rotors of SynRel motor to increase the robustness of the rotor structure for high speed operations. However, the presence of these ribs degrades the electromagnetic performance of the motor such as saliency ratio and average output torque due to the flux path oriented along q-axis, through the rib area. Hence, the selection of appropriate shape and number of support ribs are essential to ensure the robustness of the rotor without much affecting the required torque density. Present paper uses Finite Element Analysis (FEA) to study electromagnetic as well as mechanical performance of SynRel motor. Rotor structure employing variable width for radial ribs is proposed. The use of variable width in radial ribs decrease the inductance oriented along qaxis, thus improving the saliency ratio and average output torque of SynRel motor. A 1 kW prototype is fabricated for the proposed rotor structure. A detailed comparison between the conventional and proposed rotor structure is also presented to demonstrate the advantages of the latter for high speed and high torque density applications.