Modified direct instantaneous torque control of switched reluctance motor with high torque per ampere and reduced source current ripple

摘要

This paper presents a modified version of direct instantaneous torque control (DITC) for minimizing torque ripple in switched reluctance motor (SRM). In DITC, it is observed that the phase current profiles and torque ripple characteristics depend on the turn-on instant. For current profiles with low RMS value, an overshoot in torque is observed during the commutation period, which increases the torque ripple. This overshoot in torque can be limited by delaying the turn-on instant. Consequently, the resultant current profiles have higher source current ripple, higher RMS value and thereby, lower torque per ampere ratio. In order to address these limitations, a modified version of DITC is proposed for a three-phase SRM, which simultaneously improves the torque per ampere ratio and prevents torque overshoot. In addition, the proposed strategy also aims at improving the source current ripple, by reducing its peak values during the commutation period. Finally, the improved performance with modified DITC is verified by simulation studies.