An Overview of the Second Harmonic (2ω) Passive Power Decoupling Technique of 1-Phase ZSI/QZSI to Eliminate/Minimize Low-Frequency Power Ripple.

1ϕ Z/quasi-Z source (ZSI/qZSI) inverters are nowadays increasingly used in a variety of power applications like renewable energy. During the rectification process of AC to DC side, the low-frequency ripples (2ω) are present in the DC side inductor current, capacitor voltage and also in DC-link voltage. These low-frequency ripples are the double line frequency power ripples that occur at two times the fundamental frequency i.e. at 100 Hz. In the case of renewable energy applications such as PV and fuel cells, these ripples are most hazardous. Due to current and voltage (2ω) ripples, the extraction of power from PV/fuel cell reduces. It also decreases its lifetime. These low-frequency ripples also increase the output current and voltage distortion. Ultimately it affects the performance of a system and degrades its power quality. Passive power decoupling techniques are used to eliminate/reduce low-frequency power ripples (2ω). The primary contribution of this article is to show a comprehensive overview of the passive power decoupling technique for the second harmonic (2ω) power elimination over two decades. This article also provides a proposed modified control strategy that achieves the elimination/reduction of (2ω) ripple in inductor current and capacitor voltage at the lowest values of qZS inductor and capacitor. The simulation and experimental results are also obtained for the proposed model. [ABSTRACT FROM AUTHOR]