Design aspects of medium power double rotor radial flux air-cored PM wind generators

The electromagnetic and mechanical design aspects of optimally designed double rotor radial flux permanent magnet wind generators with non-overlap air-cored (iron-less) stator windings are analyzed in this paper. The optimal design is based on an accurate analytical model and is confirmed with finite element analysis. It is shown, amongst other things, that the electromagnetic design and not the mechanical design surprisingly, determines the rotor yoke dimensions and, hence, largely the mass and cost of the generator.