Diagnosis of fuel cells using instantaneous frequencies and envelopes extracted from stack voltage signal

The work carried out aims to diagnose fuel cells with reduced instrumentation and computation times. The article describes a non-intrusive, application-oriented diagnostic tool, based on the sole measurement of the stack voltage and requiring no specific external excitation of the electrochemical generator. The adopted data-driven method relies on well-suited signal analysis techniques (fast calculations of relevant fault signatures based on envelopes and instantaneous frequencies) and information processing (pattern recognition). A wide range of operating regimes can be identified (variations in flow rates, pressures, temperatures; combinations of simultaneous faults), even when they correspond to small deviations from nominal conditions. The portability of the method has been studied on two PEMFC stacks, designed for different applications: transport and stationary. Correct classification rates close to 98% are obtained in both cases.