Design, Modeling, and Control Strategy for a 30-kW PEMFC-Based Small Green Ship

In recent decades, renewable energy systems (RESs) have attracted considerable attention due to their sustainability, cost-effectiveness, and environmental advantages over fossil fuels. Among various RES technologies, proton exchange membrane fuel cells (PEMFCs) have emerged as a promising solution, particularly in marine applications. To address the limitations of standalone fuel cells in meeting dynamic load demands, hybrid energy storage systems (HESSs), which integrate PEMFCs with batteries and supercapacitors, have been widely adopted, enhancing system responsiveness and energy reliability. In this study, a fuzzy logic controller is employed for PEMFC regulation, and a state machine approach is used to control the HESS components. The proposed fuzzy state-machine EMS is evaluated against fuzzy–PI and fuzzy-based controllers; across representative duty cycles it reduces hydrogen consumption by 33.1% and 32.4%, respectively, and increases PEMFC stack efficiency by 4.42% and 18.65%, demonstrating suitability for real-time HESS energy management.