Eddy current loss minimization in rotor magnets of PM machines using high-efficiency 12-teeth/10-slots winding topology

Using winding coils with different turns per coil side for the fractional slots, tooth-concentrated winding it is possible to reduce or even to cancel some space harmonics of low order resulting in lower rotor losses induced by the armature reaction field. This technique is applied to the 12-teeth/10-slots winding during investigation of the eddy current losses for two PM machines. The obtained results show that, using the new winding the magnet losses are reduced by about 80% compared with the conventional winding.