Torque ripple analysis of three-phase induction machines with Non-Uniform Coil Groups Distribution

In this paper, the torque ripple of three-phase induction machines with Non-Uniform Coil Groups Distribution (NUCGD) is analyzed. A three-phase, 4-pole with 36 stator slots is modeled using Finite Element Methods (FEMs), first applying the convention double layer with uniform coil groups distribution and then the proposed double layer with NUCGD stator winding arrangements are applied. A conventional three-phase, 4-pole, 1.5 KW, 36 stator slots, 28 rotors bars has been used to wind different prototypes. The experimental and simulation results of the Conventional Double Layer (CONV-DL) windings are compared to those with NUCGD. The prototype three-phase induction machines designed with NUCGD stator winding reduce significantly the effect of the 7^th, 11^th and 13^th spaces harmonics. The proposed machine topologies provide advantages that many warrant its application despite an average torque density penalty.