Non-intrusive hydrogen consumption monitoring in a PEM fuel cell system using combined experiments and simulation

Accurate hydrogen-consumption measurement in proton exchange membrane fuel cell systems remains challenging when direct access to the hydrogen circuit is limited. This study presents the practical implementation and experimental demonstration of an enhanced oxygen balance method (OBM) for non-intrusive hydrogen-consumption estimation using cathode exhaust measurements, extending the conventional OBM formulation by explicitly accounting for hydrogen detected at the cathode outlet. The method was experimentally assessed on a 5 kW PEMFC platform under dynamic current operation and showed an average deviation of 8.6% relative to manufacturer beginning-of-life reference data; this figure reflects deviation from a manufacturer reference with its own tolerances, suggesting good agreement, even in the absence of an independent traceable hydrogen-flow measurement. Also, a PEMFC and balance-of-plant model was implemented in AVL Cruise-M and benchmark-calibrated against manufacturer reference data. The model reproduced hydrogen consumption with an average error of 0.43%. Together, the experimental and numerical results provide a practical framework for PEMFC hydrogen-consumption assessment, stack benchmarking and non-intrusive diagnostic support. Although demonstrated on a marine prototype, the sensing architecture was developed for transfer to automotive fuel cell systems, where direct onboard hydrogen measurement is often limited.