Isolated boost converter based high step‐up topologies for PV microinverter applications

Abstract

In this study, a family of isolated boost DC–DC converters is proposed and evaluated. This family is built by the combination of an isolated current fed converter with high-voltage gain techniques. The evaluated cells are switched inductor, switched capacitors, reduced redundant power processing and a mixed of switched inductor and switched. So, the proposed family has four different isolated high step-up DC–DC converters. To evaluate this family, a comparative study of the significant features was performed. This study comprises features such as principle of operation, derivation of static voltage gain, current and voltage stress on the components, component stress factor, number of components, power losses, power density and cost. By these evaluations, the key features, limitations and restrictions of each converter were acknowledged. In this way, one can gather all the theoretical knowledge of each of the analysed converters and estimate which one will have better performance in the laboratory. To validate the theoretical analysis, four prototypes were built according to PV AC-module specifications 200 W.