First results obtained with an impedance meter developed for the diagnosis of large Proton-Exchange-Membrane Fuel-Cell stacks

A novel architecture of impedance spectrometer is developed in order to diagnose large proton-exchange-membrane fuel-cell stacks. The new device allows also impedance measurements of individual cells located in the middle of stacks, where common mode potentials are usually too high for commercial impedance meters. This capability allows highlighting any singular cell behaviors or drift effects due to operational physical parameters (stack temperature, reactant flows...). First characterization and validation of the diagnosis instrument have been done using the results obtained with a commercial spectrometer.