A review on harmonic elimination and mitigation techniques in power converter based systems

With the increased usage of power electronics at the source and load ends of modern power systems, power quality issues like harmonic control and total harmonic distortion (THD) minimization are being given considerable attention. Selective harmonic elimination and mitigation (SHE and SHM) are well-known effective techniques to control the low-order harmonics in the voltage and current waveforms generated by DC–AC converters, which otherwise pollute the grid waveforms and lead to undesired losses. As these methods also result in lower switching losses, they are mostly beneficial for high-power applications like medium-voltage electric drives and grid-connected systems. This work presents an over-the-decade overview of the enhancements in the SHE and SHM pulse width modulation (PWM) techniques of two-level and multilevel DC–AC converters, discussing various problem formulations and the solving methods of the resulting transcendental expressions. The exclusive use of metaheuristic techniques, neural networks, and predictive control structures in expression solving and controller architecture are discussed. The current and future research directions are presented with a focus on optimization, digitalization, real-time implementation, and low-power application avenues.