Review of axial and radial flux PM machines with emphasis in high power density

A comparison between radial and axial flux machines is made, based on a review of multiple publications presenting analytical models and finite element analysis. The aim is to determine the most appropriate topology as to obtain the highest power density from one of the two topologies, given analogous operating conditions and geometrical parameters. From a unified sizing model, the axial flux machine is determined to offer higher power density. Multiple features are found to enhance the power density of the axial flux machine as the reduction in mass of electromagnetic materials and the increment of the airgap area under specific constraints.