Design of dual structural axial flux permanent magnet generator for small wind turbine

This paper presents the electromagnetic structure design analysis and the cogging torque reduction design of slotted-axial flux permanent magnet generator. The cogging torque would be a source of acoustic noise and vibration, torque ripple. To reduce cogging torque; firstly, the design of the permanent magnet skew to reduce cogging torque is studied. Secondly, the design of the stator displacement to reduce the cogging torque is studied. Finally, the combined design optimization considering both permanent magnet skew and the stator displacement to reduce the cogging torque is studied. For this study, 3-dimensional finite element method is applied for the electromagnetic analysis because of three dimensional electromagnetic structure of axial flux permanent magnet generator.