The paper presents how the performances of an electric microgenerator with double excitation used in aeronautical applications have been improved, using special materials, with superior characteristics. Thus, if the usual ferromagnetic materials were used in the initial model, in the improved model, a modern ferromagnetic material was chosen, with superior magnetic characteristics, Supermendur (HiperCo 50), massive core for the inductor and lamination sheets for the armature. For the parts that do not have a role in the magnetic circuit of the electric machine, there has been used a synthetic material, Ketron, material with higher mechanical characteristics but with low specific weight, at the same time, minimizing the interior spaces. Finally, this paper presents comparatively the electrical characteristics for the two electric machines, the one manufactured with usual, classic materials (OL37 iron and FeSi #0.2mm for the laminations sheets), and the other one with special materials as HiperCo 50. The manufacturing technology is presented briefly for some of the parts.

Keywords: Double excitation, Electric generator, Cobalt alloys, Permanent magnets, Simulation, Testing