A Novel Five Phase Fractional Slot Concentrated Winding with Low Space Harmonic Contents

In this paper, a novel five-phase fractional-slot concentrated winding (FSCW) with 20-slot/22-pole is presented. It benefits not only the advantages of conventional FSCW, but also weak space harmonics of magnetomotive force (mmf). The winding allows eliminating the 1st sub-order harmonic. The new layout of the winding topology is obtained by a combination of stator shift technique of the winding in the slots with a special coupling of the windings (star-pentagon), using winding function theory. The high performances of the new winding layout are validated using finite element method (FEM). Compared to the conventional winding, the winding factor and the THD of mmf are improved by 1.3% and 2.2%, respectively. With the same injection of current density, the average output torque is increased by 1% and the torque ripple is decreased by 60%. The eddy current losses in the PMs at rated speed (600 rpm) and 2100 rpm speed are improved by 67% and 56%, respectively.