Low-Switching Based Improved PWM for Torque Harmonic Reduction in V/f Controlled High Power Inverter Fed IM Drive

Low Switching-based  v/f -controlled induction motor (IM) drives are incredibly susceptible to torque harmonics and their Vibrations. These consequences lead to intensifying losses, damage drive, and can even turn out into shaft failure of high power/speed drives. In literature, numerous control algorithm based on pulse width modulation (PWM) has been reported for low switching-based IM drive. Nowadays, standard PWM techniques (Sinusoidal PWM (S-PWM), selective harmonic elimination (SHE) PWM) are being used as the solution in low-switching IM drives. In this manuscript, the proposed synchronous reference frame (SRF) based P-PWM scheme is analytically evaluated to minimise the torque harmonics and its vibration in low switching IM drive. In this paper, a specific case of four switching angles per quarter cycle (Sq=4) is considered in which the optimized switching angles are obtained while maintaining the quarter wave symmetry (QWS) and half wave symmetry (HWS) nature of the waveform. The proposed approach is validated on 1hp IM drive and compared with S-PWM and SHE-PWM with respect to torque spectrum and vibration under No Load and different loading conditions. Real-time waveforms are recorded using the SRF-based P-PWM technique and the TYPHOON-HIL hardware setup to demonstrate the superior performance of the SRF-based P-PWM in comparison to S-PWM and SHE-PWM, in terms of lower torque harmonics and their vibrations.