Torque Ripple Reduction in Switched Reluctance Motors by Rotor Poles Shape and Excitation Pulse Width Modification

In this paper, at first, a 24/16 three-phase switched reluctance motor is designed, then the rotor poles shape tips corrected for reduction ripple of single-phase torque waveform. By doing this, the single-phase torque waveform has a flat surface and consequently, the single-phase torque ripple is reduced. Also, due to the commutation between the machine phases, the torque drops during this time, which are known as torque pits. To reduce the ripple torque at these points, which requires overlap between the two successive phases of the machine, the pulse width of the excitation of the machine phases is adjusted. Comparisons have been made between two types of direct current excitation and chopped current (with different pulse widths). The results show that for constant pulse width under chopped current, applying the arc and modifying the shape of the rotor poles can reduce the torque ripple by 3.4%. Also, by applying chopped current control, the torque ripple was reduced by 46.7% compared to its conventional design structure.