Design of Synchronous Reluctance Machines for Automotive Applications

This dissertation reports an appropriate design methodology for synchronous reluctance machines, their important technical issues, and possible solutions for traction applications. The synchronous reluctance machines are used in industries owing to their unique merits such as high efficiency, fast dynamic response, and lower cost. Considering these superior properties, recently, this smart synchronous topology became more attractive for electrified powertrain applications in automotive industries. However, compared to the major requirements of the traction motors such as high torque and power density, low torque ripple, wide speed range, and proper size, this machine is still under investigations. The goals of this research work are first; to identify electrical, magnetic, and geometrical parameters which are dominant in the machine’s performance, and second; to verify appropriate design methodology for achieving a higher performance for automotive applications. Hence, analytical and computer aided analysis followed by experimental examinations on prototypes are carried out to support proposed methods and address possible solutions to the machine’s technical issues for these particular applications. Accordingly, the synchronous reluctance machine’s fundamental operations, electrical, magnetic, and geometrical parameters are investigated. Analytical approach and a sizing methodology corresponding to the desired specifications are presented through the machine’s mathematical model. Design of transversal laminated anisotropic rotor structure with different geometries is studied to identify the geometrical parameters effects on the machine’s performance in particular the output torque and torque ripple. An appropriate geometrical method along with an innovative rotor lamination assembly are proposed for improving the machine’s output functions such as torque, power, and saliency ratio. Finally, the future perspective of the research work is discussed for further investigations