Evaluation of Reduced Torque Ripple in Dodecagonal Voltage Space Vector PWM Fed Open-End Winding Induction Motor Drive

Lower-order torque pulsation is a major concern in high-power drives operating at low switching frequency and in over-modulation zones at high speed. In this paper, the torque and current ripple analysis for the induction motor (IM) is investigated by employing the dodecagonal voltage space vector PWM (DSVPWM) technique. The torque ripple has been analytically estimated for DSVPWM and compared with conventional voltage space vector PWM (CSVPWM). The analytical and experimental studies establishes that the RMS current ripple is lower with DSVPWM over CSVPWM in the complete speed range. The RMS torque ripple is shown to be lower for the DSVPWM with respect to the CSVPWM during higher speed ranges, and comparable during low and medium speed ranges. Experimental validation of reduced torque ripple using the proposed system has been done on a 2.2 kW open-end winding IM drive.