Integration of renewable energy sources with energy storage devices using a novel four port converter for DC microgrid applications

Abstract In DC microgrids, integrating renewable energy sources (RESs) such as photovoltaic (PV) systems and fuel cells (FCs) with energy storage devices (ESDs) is crucial for ensuring a continuous power supply. This work presents the implementation of a Four-Port Converter (FPC) designed to seamlessly integrate an ESD with PV and FC sources while employing an efficient energy management strategy (EMS) to regulate energy distribution and meet the demands of DC loads. The proposed FPC features two unidirectional input ports for RESs and one bidirectional port for ESD integration, offering a compact and unified configuration. Mathematical modeling and simulations confirm that this design delivers a reliable, cost-effective, and stable power supply for PV systems, FCs, ESDs, and DC links. Its simplified architecture, reduced component count, enhanced voltage gain, and lower voltage stress on power semiconductors improve power management among the sources. Both simulation and experimental results validate the effectiveness of the converter, demonstrating its operation under various conditions and its capability to efficiently handle energy from multiple sources. A laboratory prototype of the proposed system, designed for a 60 V, 200 W load, was developed to evaluate energy extraction, management strategies, and the performance of the FPC. The results show that the converter achieves an average efficiency of 93.86%. Additionally, a comparative analysis with existing topologies highlights the superior performance of the proposed system.