Torque Ripple Elimination for Doubly-Fed Induction Motors under Unbalanced Source Voltage

This paper proposes a control scheme which can eliminate the torque ripple of the DFIM at unbalanced source voltage. The machine torque is expressed using the positive and negative sequence components of the voltage and current. For suppression of the torque ripple, the stator reactive power ripple is controlled to be zero. The proposed torque elimination method is verified by simulation results using PSCAD/EMTDC.