A Novel High-Step-Up SEPIC-Based Nonisolated Three-Port DC–DC Converter Proper for Renewable Energy Applications

This article introduces a new nonisolated high-voltage-gain single-ended-primary-inductor-capacitor-based multiport dc–dc converter. The boosting structures, including voltage lift cell and coupled inductor, are employed to increase the voltage gain of the suggested converter, and also the input current of the proposed structure is continuous and has a low ripple, which is appropriate for renewable energy sources. Both the inputs of this converter can operate individually or simultaneously. This topology has three ports: the renewable energy source port, the battery port, which is a bidirectional port, and the output port. In this topology, the voltage stress of three MOSFET switches is low. The low-voltage stress of switches causes a reduction in their losses and improves the efficiency of this converter. Compared with converters with similar functionality, the minimum number of active switches is used in this structure, which causes reducing the implementation cost and the control structure's complexity. Operating modes of the new topology are explained in this article. Finally, a 100-W prototype of the introduced converter is accomplished to validate the claims.