Optimal harmonic mitigation technique for high-power IM drives

The reduction of harmonic torque and ripples in low-switching VFI-based induction motor (IM) drives is a crucial consideration for improving efficiency, service life, drive damage, potential shaft failure for high-power/speed drives, and overall performance. In the literature, existing solutions to these issues involves the implementation of standardized pulse width modulation (PWM) techniques such as sinusoid modulation technique PWM (SMT-PWM) and selective harmonic reduction PWM (SHR-PWM). However, this research proposes a P-PWM-based approach to address the reduction of harmonic magnitude and torque ripple in low-switching VFI-based IM drives. The proposed programmed pulse width modulation (P-PWM)-based approach is specifically applied for three- and four-angle switching per quarter cycle (Aq), targeting the reduction of lower-order harmonic magnitude and torque ripples ranging from 6th to 6(Aq  − 1)th order. By relying on independent specifications and loading states, the P-PWM approach accommodates different Aq and higher-order harmonics. Extensive comparisons with SMT-PWM and SHR-PWM, supported by findings from a 1-hp VFI-based IM drive using a TYPHOON-HIL-based hardware setup, demonstrate the superior performance of the P-PWM approach in terms of reducing the harmonic magnitude and torque ripples.