Dynamic Modeling and Control of Hybrid Electric Vessels with a Super-Capacitor and a Lithium Battery

This paper presents a dynamic model of a dual-motor vessel powered by an integrated energy system consisting of a supercapacitor (SC) and lithium battery. The SC manages high-power demands, reducing the load on the lithium battery to enhance its lifespan and improve overall system efficiency. MATLAB/Simulink was used to simulate this model, integrating energy sources, transmission systems, traction motors, propellers, and vessel body dynamics. A rule-based control strategy (RBCS) with specific operational modes-Supercapacitor Mode, Hybrid Mode I, Hybrid Mode II, and Hybrid Mode III-was developed to effectively manage energy distribution, improving energy flow and extending battery life, which lowers maintenance costs and enhances performance. Additionally, a fuzzy control method was implemented and compared to RBCS. Results indicate that fuzzy control improves velocity stabilization by 3.8% between 750 and 1200 seconds, and reduces energy consumption by approximately 5.7% compared to RBCS, highlighting its potential for greater efficiency and control in vessel propulsion energy management.