Energy Management Strategies for Fuel Cell Hybrid Ships: Classification, Comparison, and Outlook

This paper reviews research on energy management strategies (EMSs) for fuel-cell hybrid ships and introduces a “topology–strategy coupling” analytical framework, dividing system topology into two layers: energy-unit composition and DC-bus interface topology. It also introduces key concepts, such as EMS-independent dispatchability and the dominant DC-bus voltage-regulation unit. Based on this framework, the paper explains why certain strategies are easier to implement, tune, and validate under specific interface structures by considering the impact of interface topology on hybrid system efficiency and typical EMS constraints. It presents a unified four category EMS taxonomy, treating hybrid EMSs as a distinct class, and provides cross-category comparisons of different strategies. Additionally, it discusses the consistency and validation challenges when learning-based strategies transition from simulation to onboard deployment and further synthesizes mainstream approaches for integrating lifetime/health considerations into EMSs and their corresponding degradation modeling. Furthermore, the paper conducts a quantitative synthesis of relevant studies from 2016 to 2025, statistically summarizing and presenting the distributional characteristics of energy-unit composition, strategy categories, commonly used methods, validation approaches, and the inclusion of lifetime/health factors. In doing so, it uses data to describe the current state of research and identifies the key challenges and future research directions.