A comparison between the axial flux and the radial flux structures for PM synchronous motors

Abstract

The aim of the paper is the comparison of the Axial Flux (AF) structures versus the conventional Radial Flux (RF) structures for PM synchronous motors. The comparison procedure is based on simple thermal considerations. Two motor typologies are chosen and compared in terms of delivered electromagnetic torque. The comparison is developed for different motor dimensions and the pole number influence is put into evidence. The paper reports the complete comparison procedure and the related results analysis. The obtained results show that, when the axial length is very short and the pole number is high, the axial flux motors can be an attractive alternative to the conventional radial flux solutions.

Advanced Ultra-High Speed Motor for Drilling

“…Cavagnino et al [7] have made a comparison of the radial and axial configurations from mechanical and thermal points of view. Joule losses have been calculated in both the machine topologies and generated electromagnetic torque is related to the size and weight of machine for different geometries.…”

Permanent Magnet Synchronous Motor with Different Rotor Structures for Traction Motor in High Speed Trains

“…The efficiency obtained with the PMSM structures is slightly higher with respect to the IM for all the operating frequencies of the application, highlighting greater differences for the operation at low frequencies. The most characteristic values in Table 5 were compared by using the above analytical procedures [28,29]. Air gap flux was higher in all PMSM rotor structures than the IM, especially in the SPM.…”

Prototype of an axial flux permanent magnet generator for wind energy systems applications

“…Axial flux machines are recognized for having higher torque density than their counterparts based on radial-flux. A comparison procedure using simple thermal considerations, for equal overall volume, equal losses per wasting surface unit, equal airgap, teeth, yokes flux densities and rotational speed of the two machine structures, bringing out the pole number influence, is reported in [8]. The torque density advantage of AFPM machine becomes more apparent in a design with a large number of poles.…”