Soft-Switched Three-Port DC–DC Converter for off-Grid Renewable Energy Application

This article introduces a soft-switched three-port dc–dc converter (TPC) designed for photovoltaic battery systems, exhibiting continuous current of both inputs. The proposed converter has four switches and utilizes a soft-switching cell, ensuring that all switches achieve soft-switching either at the turn-on or turn-off instant or simultaneously in both states. The proposed TPC leverages battery storage with a continuous bidirectional power flow, in addition, to enabling it to meet diverse load demands efficiently, ensures power availability in battery-alone mode without the primary power source. A comparative analysis with both soft-switched and nonsoft-switched TPCs offers new insights that have not been explored in the recent literature and highlights the advantages of the proposed converter over existing technologies. An experimental prototype with a nominal power of 260 W was constructed to demonstrate its practicality, achieving a peak efficiency of 95.5%. Testing, including assessments of steady-state performance and dynamic response to load and input voltage variations, confirms the alignment with analytical predictions, making it a compelling solution for off-grid renewable energy applications.