Hybrid hydrogen – battery fueled trains. A real-time simulation approach

The paper presents a comprehensive real-time simulation framework for hybrid hydrogen–battery trains, integrating detailed subsystem modelling, degradation assessment, and energy management design. A dynamic fuel cells/battery powertrain model is developed in Matlab/Simulink and implemented on a Speedgoat® real-time platform, enabling realistic performance evaluation and hardware-in-the-loop applications. An inverse simulation approach is adopted to analyze energy management strategies and their impact on power allocation, energy consumption, and component degradation. Two alternative energy management systems are investigated and compared through a real-world case study on a long 177.5 km non-electrified railway route in Southern Italy. Although the two strategies exhibit comparable total energy-related operating costs, they result in markedly different degradation patterns and lifecycle cost structures. A conservative fuel cell management strategy reduces fuel cell degradation and lowers the number of required replacements over a 20-year operational horizon by more than a factor of three, despite a 12% increase in hydrogen consumption. This translates into a net reduction of approximately 0.6 M€ in total lifecycle costs (9.19 M€ vs 9.76 M€), while differences in refuelling and recharging expenditures remain marginal. However, a sensitivity analysis identifies the hydrogen price as the dominant external risk, with a ±30% fluctuation impacting the total cost by approximately ±2.0 M€. Degradation-aware energy management emerges as a key design criterion for improving the long-term economic performance and reliability of hybrid railway systems. The proposed real-time simulation framework provides a robust tool to support control design, system validation, and cost-informed decision-making in next-generation sustainable rail transport.