Switched inductor‐capacitor‐based quasi‐Z source converter for renewable energy source integration

Abstract

SummaryIn applications involving renewable energy sources such as solar PV and fuel cells, the high‐gain DC–DC converter must have the following desirable characteristics: high voltage gain, continuous input current with low ripple content, common ground structure, reduced voltage stress on the components, and high efficiency. In addition, the requirement of a lower duty ratio to produce a higher voltage gain aids in reducing the converter's inductor core saturation issue. In this research, a converter employing switched capacitor–inductor cells and a quasi‐Z source network with the aforementioned features is proposed. The steady‐state analysis in both CCM and DCM is presented. The performance of the converter including the parasitic effect of converter components is analyzed. This paper also includes a comprehensive comparative analysis highlighting the benefits of the proposed converter. A small signal model and the output‐to‐control transfer function are derived. The analytical performance of the proposed converter is validated using a hardware prototype of 500 W, 50 kHz. A compensator is designed to improve the dynamic closed‐loop performance and validated experimentally. The experimental findings for boosting 48 V input to 650 V output are provided. The results prove that the proposed converter has the advantages of high gain with a lower duty ratio, low voltage stress on components, continuous input current with low ripple content, and a common ground structure.