Design of switched reluctance machines for low-acoustic-noise and wide-speed-range operation

The dissertation presents a comprehensive design methodology encompassing the effects of machine geometry, configuration, material properties and parameters on the overall performance of the SRM. The developed methodology is verified with system level simulations and finite element analysis (FEA) and experiments.; Two analytical methods have been developed for calculating stator mode frequencies. The first one is the ‘simple method’ having closed form equations that are used for prompt realization of any structural variation of the stator during the design process. The second one named ‘matrix method’ calculates the circumferential mode frequencies including the effects of end-shields and frame attached to the stator structure. An analytical-model has also been developed to find the magnetic radial force in an SRM. The radial force model is used for predicting the noise power level taking only the circumferential mode shapes and frequencies into consideration. The noise prediction model is utilized in the comprehensive design methodology to develop guidelines for selecting configurations, parameters and geometries for a low-noise SRM.; The current research demonstrated the usefulness of two critical rotor positions for an SRM drive requiring extended constant power range. A geometry-based algorithm is developed to determine these critical rotor positions for the SRM. The dissertation provides a design strategy towards extending the separation between these critical rotor positions for a wide-speed-range SRM.; Experiments were conducted to acquire acoustic noise and torque-speed data of the SRM designed and built according to the developed design methodology. The experimental results correlate satisfactory with the theoretical predictions.