Novel synchronous reluctance motor with sinusoidal rotor lamination shape for less torque ripple contents

Abstract: This paper presents the analysis of a novel Synchronous Reluctance Motor (SynRM), which has an axially sinusoidal rotor lamination shape. The sinusoidal lamination shape is used to vary magnetic flux in the q-axis direction. Therefore, cancelling some torque harmonics produced by stator slotting effects and rotor anisotropy, while maintaining the average torque. The stator of a 5.5 kW, 4-pole, 50 Hz conventional three-phase squirrel cage induction motor, with distributed and chorded by one slot, double layer winding, is used for both standard and novel motors. The Finite Element Analysis (FEM) is used to study the electromagnetic parameters of interests. The FEA results are validated by means of practical measurements. The results obtained from both FEA and practical measurements evidenced that the novel SynRM dropped tremendously the torque ripple contents while still maintained the average torque. The drop in torque ripple contents is mainly due to mitigation of the most dominant torque harmonics caused by stator slotting and rotor anisotropy