Multi-physics design and analyses of dual rotor synchronous reluctance machine

Abstract

Dual rotor topology of synchronous reluctance machine is here proposed to improve the motor torque density and reduce the torque ripple. Thus, allowing synchronous reluctance machine to merge into EV and HEV applications. This paper presents a multi-physics design and analyses of three double rotor synchronous reluctance machine, 24/4, 36/4 and 48/4 stator slot/rotor pole combinations, through electromagnetic, mechanical and thermal analysis. First, a genetic algorithm optimization process linked to magnetic FEA has been used. The optimization is set to target the highest torque, lowest torque ripple and core loss. Mechanical study and investigation of the magnetic and rotational forces on the rotor ribs and stator tooth-tip structure have been considered to guarantee the mechanical robustness. Furthermore, the design assembly structure to ease heat dissipation from the stator has been investigated thermally. Finally, a comparison with a conventional single-rotor synchronous reluctance machine having the same size and operating conditions have been made to highlight the advantages of the double rotor synchronous reluctance machine. From the comparison it has been concluded that the double rotor machine produced 45% higher torque and 40% less torque ripple compared to its single rotor counterpart. Synchronous Reluctance Machines, Double Rotor Machine, Structural Analysis, Double Airgap Machines. • The design of a novel double rotor synchronous reluctance machine is presented. • A multi-physics design process and genetic algorithm global optimization are used. • The double rotor machine showed higher power density when compared to the single rotor. • Lower torque ripple is found in the double rotor machine when compared to the single rotor. • The higher power density and lower torque ripple are essential for automotive application.