Performance Analysis of Proton Exchange Membrane Fuel Cell Systems Under Different Air Compression Strategies for Aviation Applications

The aviation sector is under pressure to reduce greenhouse gas emissions. Proton exchange membrane fuel cell (PEMFC) systems are considered a promising option for sustainable aviation because of their high efficiency and suitability for electric propulsion. However, their performance deteriorates at high altitudes because reduced ambient pressure lowers the oxygen partial pressure at the cathode. This study investigated aviation PEMFC systems employing different air compression strategies under aircraft operating conditions. Three air supply configurations were examined: no compressor, a single-stage compressor, and a double-stage compressor. Among these, the double-stage configuration most effectively improved the reactant supply and stack output at high altitudes. Although the double-stage configuration increased compressor parasitic power consumption and required additional heat rejection through intercooling, its higher gross stack output compensated for these penalties and produced the highest net output. Achieving the same output with the no-compressor or single-stage compressor configuration would require additional cells and a larger stack. The system-specific power analysis showed that the double-stage configuration provided the most favorable mass-based performance. These results suggest that a double-stage-compressor configuration can be an effective air supply strategy for aviation PEMFC systems under high-altitude conditions.