Performance and implementation issues considering the use of thin laminated steel sheets in segmented armature axial-flux PM machines

For yokeless and segmented armature (YASA) axial flux permanent-magnet machines, several lamination stacking methods are discussed. For the same global machine geometry, it is shown that some are easier and cheaper to produce, while others have a higher output torque, lower cogging torque, better efficiency or higher power density. Apart from the different lamination stack geometries, also different magnet geometries are studied. By evaluating the different combinations of lamination stacking methods and magnet shapes, it is shown that some combinations suffer from local saturation, lower output torque and higher losses. The simulations are performed by a multilayer 2D and a simplified 3D finite element model. To prove the validity of the proposed model, simulated results are verified with measurements on a prototype machine.