This article addresses dual rotor axial flux Ferrite permanent magnet (PM)
generator, as an alternative to a surface mounted and spoke types Nd-Fe-B
generator which have concentrated windings. The performance parameters of
all generators, particularly the efficiency, are identical. The design
objective function is the generators mass minimization using a
population-based algorithm. To predict the performance of the generators a
finite element (FE) technique is applied. Besides, the aims of the design
include minimizing cogging torque, examining different rotor pole topologies
and different pole arc to pole pitch ratios. Three-dimensional FE technique
is employed. It is shown that the surface mounted Ferrite generator topology
cannot develop the rated torque and also has high torque ripple. In
addition, it is heavier than the spoke type generator. Furthermore, it is
indicated that the spoke type Ferrite PM generator has favorable performance
and could be an alternative to rare-earth PM generators, particularly in
wind energy applications. Finally, the performance of the designed
generators is experimentally verified.