Model-Based Design and Energy Management of an Aeronautical Proton Exchange Membrane Fuel Cell System

The growing demand for air transport requires efficient and sustainable power systems to meet the pressing need for decarbonizing the sector. A hybrid unit, consisting of a proton exchange membrane fuel cell system and a lithium-ion battery, is a suitable option due to the benefits of reduced gravimetric and volumetric impacts, along with the flexibility of energy management strategies. This work addresses, using a model-based approach, the issue of integrating these electrochemical devices into the aircraft’s electrical architecture, considering both design and energy management aspects. Two scenarios are explored to match the DC bus line voltage requirements. In the first, the fuel cell system nominal power is kept constant, while the number of DC/DC converters operating in parallel is assessed by constructing bi-dimensional maps derived from literature. These maps relate the converter’s maximum deliverable power to the input and desired output voltage. The second scenario introduces the fuel cell system power rating as an additional degree of freedom to be optimized, in order to respect both DC bus constraints and minimize hydrogen consumption. As additional contributions, the auxiliaries’ power absorption and heat generated by the stack are also estimated, providing insights for the preliminary sizing of the thermal management system. The proposed strategy exhibits a reduced calculation time, thus contributing effectively to the simulation of complex integrated systems as that of hybrid electric aircraft with more electric onboard systems.