Design and analysis of low torque ripple switched reluctance motor using 3-dimensional finite element method

Switched reluctance motors (SRMs) are receiving significant attention from industries in the last decade. While switched reluctance motors have good performances, such as high torque, high speed, and high reliability, SRM has serious disadvantage of large torque ripple due to its the geometric characteristic, that is, saliency of the stator and rotor which causes undesirable acoustic noise and vibration. In order to reduce the torque ripple and improve the average torque of the motor, this paper introduces a new configuration for a switched reluctance motor. The proposed novel motor consists of two magnetically independent stator sets (layers) and a rotor set. Each stator set has a 7.50 angular shift in position from the another stator set, whereas in the rotor set there is no shift. In this motor each stator set includes twelve salient poles with windings wrapped around them, while the rotor comprises of eight salient poles, which will be engaged in the low torque ripple production mechanism. The performances of proposed type of SRM were confirmed by 3D finite element analysis, also advantages and limitations of using flux barriers in the SRM designed for low torque ripple are discussed. From the analysis results, it must be noted that the proposed type has great advantage over the conventional type toward trend of lower torque ripple per a volume. Analysis results are presented, to validate the inserting the flux barriers and the resulting improvements.