Comparison of concentrated winding permanent magnet motors with embedded and surface-mounted rotor magnets

This paper addresses the torque production and losses of concentrated winding permanent magnet motors. These synchronous motors having either semi-closed slots or open slots with two different rotor structures are studied. The rotors have either embedded magnets or surface magnets. Embedded magnet rotors are in some cases easier to manufacture than surface magnet rotors, and therefore, it was in the authors' interest to study and compare these two basic constructions. In open slot concentrated winding motors, it is possible to use prefabricated coils, which leads to low-cost and fast stator winding manufacturing. Hence, this stator type is the most interesting one to be studied. Different slot and pole combinations are considered based on the finite element analysis (Flux2D by Cedrat is employed in the computations). Index Terms--Concentrated winding, embedded magnets, open slots, permanent magnet motor, rotor surface magnets, semi-closed slots.