Design of high-performance synchronous reluctance motor for hybrid electric vehicle application

Abstract

This paper presents the simulation-based design of a synchronous reluctance motor (SynRM) coupled electromechanical system suitable for the hybrid electric vehicle. The study considers SynRM with a 75kW power rating with the capability to produce up to 125kW maximum power for the electric vehicle. The focus is mainly on rotor and stator design; the angles of the flux-barrier ends are considered to reduce the torque ripple due to the slot harmonics. Reluctance machines are indeed competitive for applications requiring high efficiency at low cost. However, it is a challenging task to find design solutions that ensure structural integrity of the motor without compromising its overall performance, particularly in the presence of optimized rotor flux barriers. The impact of electrical design on the mechanical characteristics of the rotor is discussed as well. The overall design and comprehensive of electromagnetic finite element analysis are conducted using Ansys Motor CAD software. In the results analysis, the predicted mechanical characteristics of the reluctance motor, such as torque versus speed behavior, power losses, and power factor, are presented. The efficiency map of the designed SynRM is also discussed in the whole operating region, indicating a high performance is achieved as compared to the existing design. The absence of rotor winding in the robust rotor design and proper arrangement flux barrier has led to more than 30% reduction in copper losses, improved thermal performance, increased mechanical robustness, and simplified manufacturing processes compared to the induction motor. Compared to similarly size Synchronous motor, the proposed design exhibits consistently superior efficiency beyond 1,000 rpm, delivering relatively 18% and 43% higher power output at 4,000 rpm and 8,000 rpm, respectively