A Single-Phase Outer-Rotor Generator Featuring Permanent Magnets and Conductive Shield

Electric users such as houses and small businesses are usually supplied from the utility through a single-phase low voltage feeder. Anyway, especially in developing countries the grid is often not much reliable: in such cases, autonomous generation systems are often sought as a temporary back-up. However, such systems shall be as simple, inexpensive and reliable as possible. This paper describes a 1-phase generator designed upon industrial request for such purpose featuring some peculiarities: outer rotor, direct output, no voltage regulator, permanent magnets excitation and a conductive shield able to mitigate by means of eddy currents the adverse effects of the reverse m.m.f. wave due to armature reaction. The proposed design is validated by means of finite elements electromagnetic simulations, proving to be a viable solution.