Design and Analysis of a Field-Modulated Permanent-Magnet Direct-Drive Wind Power Generator with Non-uniform Distribution of V-shaped Magnets

Wind power generation is an effective measure for addressing both the energy crisis and environmental pollution. Field-modulated permanent-magnet motors (FMPMMs), with their high torque density and efficiency, eliminate the drawbacks of gearboxes and are very suitable for direct-drive wind power generation. This paper proposes a new field-modulated permanent-magnet generator (FMPMG) with non-uniform distribution of V-shaped magnets (FMPMG-NDVM), aiming to reduce the permanent-magnet (PM) usage and mitigate torque ripple. Firstly, the structure of the proposed generator is introduced; then, its working principle is introduced and a 18/12-pole FMPMG-NDVM is designed. Next, the electromagnetic performance of the designed generator is evaluated by using 2D finite element method (FEM), including cogging torque, induced electromotive force (EMF), inductance, electromagnetic torque, efficiency, etc. Finally, a comparison is made with a FMPMG with uniform distribution of V-shaped magnets (FMPMG-UDVM), and simulation results confirm that the proposed generator has achieved the initial goal.