Comparison between three iron-powder topologies of electrically magnetized synchronous machines

The finite element method has been used to analyse three topologies of iron-powder electrically magnetized synchronous machines. The first topology has the field winding placed in magnetically conducting end-plates, eliminating the need of slip-rings. In the second topology this is achieved by placing the winding above the outer rotor, and the third topology corresponds to the more conventional design with the field coils in the rotor. The results show that the first topology outputs 60% more torque than the other designs, although the three topologies present similar characteristics with regard to torque densit