Permanent magnet axial flux disc generator for small wind turbines

In the paper a permanent magnet axial flux disc generator (AFPMG) with fractional slot pitch winding for small wind energy applications is proposed. Its main features are high specific power, very low torque ripple and a quasi-sinusoidal output voltage. A preliminary design can be carried out by a simplified analytical procedure. Afterwards, an automated sequence of magnetostatic FEM analyses on rectified 2D AFPMG models enabled to examine more in detail the influence of parametric variation with a considerable reduction of calculation time with respect to 3D analyses, to improve the generator performance, fulfilling the design constraints. The comparison with the results of some 3D FEM analyses confirmed the good accuracy of the proposed design approach. Furthermore, the results related to the simulation of an AFPMG-rectifier drive will be presented.