Permanent magnet volume minimization in permanent magnet assisted synchronous reluctance motors

In the recent years the study on new motor topologies for automotive applications has found an increasing interest. The environmental impact of conventional internal combustion engine, together with the increasing demand and the cost of the oil, are two of the main reasons that makes electric motors an attractive alternative. Machines that employ interior permanent magnet configurations are widely recognized as good performance motors for traction applications. On the other hands, the exponential increase of the price of rare earths magnets in the last years, is making rare earth motors a very expensive solution. This encourage the research of low cost, rare earth free alternatives, represented by the permanent magnet assisted synchronous reluctance machines. Three different magnet dimension configurations have been considered. This research highlights the influence and benefits of the insertion of ferrite on the machine performance, emphasizing the importance of a careful evaluation of the magnet quantity in order to optimize the performance and reduce the total cost.