Field Analysis of Dual Stator Winding Induction Machine

Basic concepts of six-phase ac motor drives have existed for a number of years ago and were considered extensively in the eighties for safety-critical and/or high power applications. There has been an upsurge in the interest in these drives in recent times, initiated by various application areas, such as 'more-electric' aircraft, electric ship propulsion and EV/HVs. In our study, an ac drive with dual stator windings fed by dual six step converters is proposed. Two sets of electrically isolated windings are placed in the stator slots, and one set is shifted from the other by 30 degrees in space. Two converters are used to fed the dual windings, and the phase voltages from the two converters are also shifted 30 degrees from each other in time. The 5th and 7th harmonics of the air-gap flux and rotor currents are reduced dramatically. However, for each individual converter, the 5th and 7th harmonic currents are found to be substantial and the functioning of the power converter evidently is deteriorated. In this paper, the computer-simulation of the dual-stator-winding induction machine using FLUX2D software in which the space harmonics of the stator windings and those of the rotor circuits are accounted for has been presented.