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This work aims to present the study of synchronous electrical machines with permanent magnets for use in wind turbines, where the rotor, usually built from laminated sheets of low carbon steel and FeSi, will be replaced by sintered alloys obtained from Powder Metallurgy. Thus, in this work, studies will be conducted in order to verify the feasibility of using pure iron and some sintered alloys, such as FeSi and FeNi, to construct the referred rotor. These materials will be characterized in terms of their physical properties as well as simulations of the machine will be carried out in three different topologies of the rotors. Two machines have the magnets bonded to the surface of the rotors, with two different configurations, namely straight poles and poles protruding, and the third one has the magnets inserted inside the rotor core. The simulations results of different topologies pointed out that for machines with rolled sheet, the best-sintered alloy in order to replace the rotor core would be Fe-2%P. The worst case would be the machine with magnets embedded having the other two similar torque results. [ABSTRACT FROM AUTHOR]

The purposes of this paper were to study the thermal treatment of Fe-Si sheet, as well as the sheet cutting concerning the topology of a mini stepper motor and mini motor simulation using finite element software. The research consisted of the execution of an "Inductive Reheating" thermal treatment of Iron Silicon sheets, NM71-2000/35F 420M with GNO (Grain Non Oriented), and 0.35mm width. The new technique has the benefit of minimizing magnetic losses produced by the cut on the edge of electric sheets. To carry out the process, the system includes a furnace, an induction coil, and a power supply that, when activated in a controlled way, causes relevant changes to the crystalline structure of the material. Related to the cut of the sheets, the topology of a three phase mini stepper motor was considered. The sheets were initially cut using the geometry of the rotor and stator cores. Firstly, a die cutting process was used and later a wire electroerosion cutting process was employed, which provided parts with excellent finishing. Finally, the mini motor was simulated using the finite element software FEMM 4.2 in order to analyze the airgap flow and torque development of the axis end, in comparison to a solid block of the same material (Fe-Si). [ABSTRACT FROM AUTHOR]