Optimal operation of maritime hybrid fuel cell/battery power systems via a real-time energy management approach – A tugboat case study

• Develops scalable and modular dynamic models for hybrid hydrogen fuel‑cell/battery marine power systems. • Develops an ECMS–ACO‑based real‑time energy‑management strategy that enhances performance and lifetime of fuel‑cell and battery systems. • Utilizes real tugboat operational energy‑consumption data to emulate realistic mission profile. • Demonstrates the advantages of real‑time EMS implementations over conventional rule‑based strategies. • Discusses different on‑board hydrogen storage technologies and their implications for marine vessels. Zero-emission power systems for marine vessels need to be developed to meet the International Maritime Organization goals to reduce greenhouse gases in shipping industry. Hybrid proton-exchange membrane (PEM) fuel cells/lithium-ion battery-based power systems can be a good option for short to medium range operations in coastal areas and seaports. However, hybrid fuel cell/battery power systems require a long lifetime, low operating costs, and reliable operation. This paper proposes the design, analysis, and validation of an optimal real-time energy management strategy (EMS) for scalable and modular hybrid fuel cells/lithium-ion battery power system. A case study to assess the feasibility of a possible alternative power system solution for a tugboat operating in the Tokyo Bay area is presented. The proposed EMS is based on the equivalent consumption minimization strategy and ant colony optimization (ECMS-ACO). The proposed approach optimizes power distribution between fuel cell and battery systems in response to load demand in a reliable way, while minimizing hydrogen fuel consumption and enhancing the operability and durability of the power system. A real-world load profile of the tugboat has been used to emulate and analyze the performance of the proposed EMS. Three on-board hydrogen storage methods relevant for the shipping industry were also analyzed. The overall system configuration was modelled and simulated using MATLAB/Simulink environment. The results show that the proposed EMS can reduce the hydrogen consumption by nearly 4.76% compared to a rule-based strategy, which in turn can reduce total operating costs by more than 8.05%.