Analysis of multi-phase and multi-layer factional-slot concentrated-winding on PM eddy current loss considering axial segmentation and load operation

The effects of multi-phase and multi-layer windings of the 12-slots 10-poles surface-mounted permanent magnet synchronous machines (SPMSMs) on eddy current losses in permanent magnets (PMs) are mainly investigated using the 3-D finite element analysis in this paper. Eddy current losses in PMs considering its axial segmentation are also analyzed. It is demonstrated that dual three-phase four-layer (DTP-FL) winding layout has the minimum value of eddy current losses in PMs, when segmentation number N = 4. It is because DTP-FL winding has smaller magnitude of high-order magnetomotive force harmonics relative to other four winding layouts. The average torque and torque ripple changing with multi-phase, multi-layer, and axial segmentation are also studied. Finally, the no-load and load experiment platform for an axial flux integrated-starter generator with DTP-FL winding and radial segmented PM are established in order to validate the proposed method under power generation mode.