Nowadays, the railway sector in the European Union represents the most environment friendly transport system, being the majority of the trainlines electrified. However, electrification is not economically viable in mountain areas or for secondary lines with limited traffic. Thus, diesel trains are still in operation, producing polluting emissions. For these reasons, Fuel Cell-hybrid trains have been developed, representing a promising technology to completely decarbonize the railway sector. Fuel Cell (FC) exploit the electro-chemical reactions between hydrogen and oxygen to produce electricity with harmless emissions. Moreover, batteries allow energy storage, in addition to supply traction load, thereby improving fuel economy. Even though FC-hybrid systems allow to reduce fuel consumption and eliminate polluting emissions, the presence of two power sources arises a common challenge for hybrid vehicles, that is the power allocation among them.