Theoretic and experimental preliminary approach to the adoption of bonded magnets in fractional machines

The general problem of increasing, through the use of bonded magnets, the performances of small PM machines adopting ferrite magnets is analyzed; the general aim is the realization of motor prototypes adopting a structural solution of actual interest. After preliminary consideration some machine prototypes have been realized. The problem has been approached with the substitution of ferrite magnets with bonded ones. Different reasons brought the authors to the decision to produce some types of the necessary magnets in the internal laboratories. After an important preliminary analysis two types of bounded magnet have been selected, one of them not mentioned in the literature. Through the self produced magnets prototypes a preliminary simulation activity has been carried out, based of obtained real magnetic characteristics that brought to product different machines prototypes to test. The obtained results, allow to define very satisfactory the possible performance increment, and suggest to continue the research line.