Extraction and Energy Management of Solar Photovoltaic, Fuel Cell, and Battery Systems Using a Novel Multi Port Power Converter for DC Microgrid Applications

In DC microgrids, efficient power extraction and an effective energy management strategy (EMS) are crucial when integrating multiple power sources. This study presents a novel Four-Port Converter (FPC) configuration designed to extract power from photovoltaic (PV), battery, and fuel cell (FC) sources while employing an advanced EMS to manage energy distribution and meet the demand of DC loads. The proposed FPC features two unidirectional input ports to accommodate renewable energy sources (RESs) and one bidirectional port for integrating an energy storage device (ESD) within a unified configuration. This paper provides a detailed analysis of the converter's operation, exploring various operating modes for optimal power extraction and energy management from PV, battery, and FC sources. To achieve this, a closed-loop control strategy, along with the EMS, is implemented. Mathematical modeling and simulations demonstrate that this unified configuration ensures efficient, cost-effective, and uninterrupted power transfer among PV, FC, ESD, and the DC link. The design offers advantages such as a simplified structure, a lower component count, higher voltage gain, and reduced voltage stress on power semiconductors while effectively managing power flow among the sources. Both simulation and experimental results validate the feasibility of the proposed converter, highlighting its operational characteristics under different states and energy management modes. A laboratory prototype of the system was developed for a 60V, 200W load to assess the power extraction and energy management performance. The results confirm that the converter achieves an average efficiency of 93.86%. Additionally; a comparative analysis with existing four-port topologies and efficiency evaluations across various operating modes is presented. The findings demonstrate the superior performance of the proposed system in terms of higher voltage gain, lower switching losses, and reduced diode stress.