Сomparative evaluation of low-power off switched reluctance motors with axial or radial magnetic flux

Abstract

Introduction. Over the past decade, the interest and, accordingly, the volume of applied scientific research devoted to switched reluctance motors with axial magnetic flux (ASRM) has grown significantly abroad due to their higher specific performance compared to engines of a similar type, but with radial magnetic flux (RSRM). This work is aimed at the development of this direction in domestic electromechanics.

Methods and results. To calculate the magnetic field in ASRM, a three-dimensional finite element model was used, and for RSRM, a two-dimensional one was used in order to reduce the estimated time. Compared motors have the same number of phases, stator and rotor teeth, air gap, are equivalent in terms of creating the same torque at an equal linear current load. Relationships are obtained that establish a relationship between the main dimensions, the winding data of ASRM and RSRM, ensuring their equivalence. An assessment of the moment characteristics and weight and size indicators is given. The geometric dimensions and masses of the compared motors, the results of computer modeling are given: graphs of phase torque as a function of the position of the rotor and the magnitude of the direct current set in one phase, as well as a picture of the distribution of the magnetic field of the 3D model for one of the options for calculating ASRM. If the generated torque is equal, the active masses of the electrical steel of the cores, the copper of the windings, as well as the active volume of ASRM are less than those of RSRM, by 30,6, 22,0 and 8,4 %, respectively. ASRM was compared with two external stators and one internal segmental rotor and with two external rotors and an internal double-sided stator. Technological issues of manufacturing ASRM are briefly considered.

Conclusion. The obtained results confirm the prospects of the reluctance machine with axial flow. Due to a more detailed study of the ASRM design, the best weight and size indicators were obtained in comparison with the published data.