Synchronous reluctance motor without rotor ferromagnetic yoke

Abstract

A new construction of an outer-rotor synchronous reluctance motor without typical rotor ferromagnetic yoke is presented and investigated in this paper. The paper includes a comparative analysis between the new construction of the outerrotor synchronous reluctance motor and a similar salient-pole motor with outer ferromagnetic yoke. For the comparative analysis the electromagnetic torque-angle characteristics of the both motor types are calculated by the magnetostatic field analysis with the help of computer software QuickField. The comparison results of the both motors under investigation show that higher electromagnetic torque per unit volume can be achieved with the proposed synchronous reluctance motor design without typical rotor ferromagnetic yoke.

Design of Low-Torque-Ripple Synchronous Reluctance Motor with External Rotor

“…Pole coverage factor for such a motor is increased to 0.95-0.98, which increases specific electromagnetic torque in comparison with a motor with salient poles. Results presented in paper [4] show that synchronous reluctance motor with a segment-shaped external rotor has significant electromagnetic torque ripple. In addition, the known method of torque ripple reduction -skewed rotor packages by value of the stator slot pitch in such a motor can significantly reduce torque ripple; however, in such a case the average value of electromagnetic torque greatly decreases.…”

“…Papers [4]- [5] present the study of difference methods for reducing torque ripple, which in some cases does not have effective results. In order to find the effective solution to suppress the electromagnetic torque ripple and at the same time to maintain the average value of the electromagnetic torque, it is necessary to carry out a deep analysis of the distribution of the magnetic field in the active part of the studied machine depending on the configurations of ferromagnetic and non-magnetic parts of the rotor.…”