Torque ripple analysis of three-phase induction machines with non-uniform coil groups distribution.

Abstract: 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 7th, 11th and 13th spaces harmonics.The proposed machine topologies provide advantages that many warrant its application despite an average torque density penalty. Keywords— Induction machines, Non-u Torque ripple, Winding layouts. I. INTRODUCTIO He search for more, cost effective layouts drives design of electrical m limits. However, experience with many both in industry and in the field of conversion has shed light on the short conventional arrangements such that th embrace new winding topologies [1]. Conventional windings for polymachines are layed out in one or two-lay [3]. The total number of coils equals ha stator slots for single layer configurati number of stator slots in double-layer co pitched and short-pitched are used d application [4]. Windings are built with in slots per pole and per phase [7], [8]. However, most electric machine de fundamental flux wave theory [2]. Attenti on the achievement of sinusoidal flux de with as little harmonic content as p fundamental component of resultant ai distribution in interaction with the fundam M. Muteba is with Tshwane University of Techn Electrical Engineering, Private bag X680, 0001, Pret (E-mail: mbikachris@webmail.co.za). A. A. Jimoh is with Tshwane University of Techn Electrical Engineering, Private bag X680, 0001, Pret (E-mail: jimohaa@tut.ac.za). D. Nicolae is with Tshwane University of Techn Electrical Engineering, Private bag X680, 0001, Pret (E-mail: danaurel@yebo.co.za). T Torque Ripple A Machines wi M ipple of three-phase m Coil Groups e-phase, 4-pole with Element Methods double layer with he proposed double ements are applied. W, 36 stator slots, 28 ent prototypes. The the Conventional compared to those induction machines uce significantly the onics. The proposed at many warrant its ty penalty