REDUCTION OF EDDY CURRENT LOSS OF PERMANENT-MAGNET MACHINES WITH FRACTIONAL SLOT CONCENTRATED WINDINGS

Abstract

Fractional slots concentrated windings (FSCWs) are characterized with high magnetic motive force (MMF) harmonics which results in undesirable effects on permanent-magnet (PM) machines. A new design technique is reported in this paper in order to simultaneously reduce the sub- and high MMF harmonics. By using multiple layer windings and different turns per coil, a new 18-teeth/10-poles FSCWs PM machine is designed. Then, this machine is evaluated as compared with a conventional 12-teeth/10-poles FSCWs PM machine. Both machines are designed under the same electrical and geometrical constrains. The obtained results verify the high performances of the newly designed machine. Due to the adopted new winding type, the proposed design can effectively reduce eddy current loss in PMs as compared with the conventional design.