Influence of magnetic wedges on the no-load performance of axial flux permanent magnet machines

Axial flux permanent magnet (AFPM) machines are being increasingly used in a variety of industrial, direct drive applications which benefit from their extreme axial compactness. In particular, slotted type AFPM machines are of great interest, since they allow to achieve high torque densities together with an adequate constant power speed range. This paper analyzes a particular aspect related to the design of such machines, i.e. the use of soft magnetic composite (SMC) wedges to close stator slots. 2D and 3D finite element analyses (FEA) are performed on a 10 kW AFPM machine adopting various magnetic wedge configurations; the no-load performance is compared with that of the same machine using non-magnetic wedges in terms of flux linkage, cogging torque and no-load losses.