Synchronous reluctance machine design considering slotting effect and rotor topology optimization

Abstract

This research explores design criteria for a synchronous reluctance machine (SynRM) with a four-layer rotor flux barrier structure with different design shapes. The main focus is to investigate slot harmonics and the angle influence of rotor flux barrier ends on the machine’s electromagnetic and structural performance. Firstly, an analytical relationship is derived between the slot harmonics, flux barrier angle, and its impact on the machine’s electromagnetic performance. An optimization analysis is conducted for different rotor flux barrier design shapes, focusing on the impact of angle variation of flux barrier ends on the airgap flux density, torque, torque ripples, radial forces, vibration, and noise behaviour of SynRM designs. A performance improvement method based on flux barrier ends angle optimization for SynRM is proposed through the cancellation of phases between the fundamental wave and slot harmonics. The best and worst design scenarios for SynRM design obtained through angle variation of the flux barrier ends are explored considering its electromagnetic and structure performance metrics. The proposed method and optimization technique are validated for different designs of SynRM with fluid shapes and straight segmented shapes flux barriers under different slot pole combinations. The suggested angle optimization method for flux barrier ends significantly minimizes torque ripple and enhances the electromagnetic and vibro-acoustic behaviour of SynRMs, thus expanding their applicability across various application areas.