| Firstly, the performance of multiphase concentrated winding induction machines specifically designed for operation with static power converters is described. The winding distributions are intentionally rectangular to better accommodate the rectangular wave forms of solid state inverters. Fourier analysis has been used for investigation of the effects of different air-gap field spatial distributions and time harmonics in the supply. Equations which define the transient as well as steady state behavior including the computation of all machine inductances have been derived. Calculation of terminal voltages and electromagnetic torque have also been modified to account for non sinusoidal air gap flux distributions. The approach to analysis of such machines is implemented by means of a digital computer simulation. Computed results indicate that when operating in conjunction with a converter supply, a specially wound five phase induction motor is theoretically capable of at least 14% improvement in torque per rms ampere assuming the same peak flux density level in the rotor tooth of the machine as in a conventionally designed induction motor of the same rating.; A converter optimized five phase induction motor drive is designed and evaluated in this thesis. The associated converter utilizing IGBT devices and controller have been built. The experimental five phase induction motor has been tested in the lab and compared to a three phase, conventionally wound, six step current regulated PWM induction motor. Further suggestion for better improvements are proposed for the future work.; Secondly, an alternative topology for a synchronous reluctance motor (SRM) is proposed utilizing a novel five phase, concentrated winding, wye connected stator. It is shown that this machine is capable of producing about 12% more torque per rms current than the normal three phase SRM. The linear analysis are backed by a more detailed finite element model. Again suggestion for higher torque capability are given at the end. |
