Finite element method based design and analysis of a low torque ripple double-stator switched reluctance motor

Abstract

Double-stator switched reluctance motors (DSSRMs) acquire attention because of their high torque/power generating capability compared to conventional and segmented rotor switched reluctance motors. One of the main limiting performance indices of such motors for industrial applications is its high torque ripple. This paper proposes a 12/10/12 pole DSSRM with an angular shift of half of the stroke angle between inner and outer stators. The respective phase windings of the inner and outer stators are parallelly excited with the same phase angle shift to reduce the torque ripple. Each rotor segment is constructed with a pair of half rotor segments that are isolated from each other through the insertion of a non-magnetic isolator between them. Firstly, the design hypothesis for a low torque ripple DSSRM has been presented; thereafter, some geometric modifications have been suggested and investigated to obtain a nearby response in the proposed DSSRM. The calculation of the width of the non-magnetic isolator, modification in the pole height of outer stator and modification in the arc angles of rotor segments/stator poles are discussed in detail. The effectiveness of the proposed motor is investigated through a 2D finite-element modelling and simulation in ANSYS/MAXWELL software. Simulation results show that the torque ripple is significantly reduced by 74.9% in the proposed DSSRM compared to the baseline DSSRM.