| In this study, the steady state performance and dynamic behavior of a commercial 10-cell PEM fuel cell stack was experimentally investigated using a self-designed and developed PEM Fuel Cell Testing Stand. The start-up characteristics of the stack to different current load and dynamic responses after current step-up were studied. The stack voltage was observed to experience oscillation at air excess coefficient of 2 owing to the flooding and recovery of part of cells. To correlate the stack voltage with the pressure drop across the cathode/anode, fast Fourier transform was performed to obtain the dominant frequency of pressure drop signal, which indicated the water behavior in cathode/anode thereby predicting the stack voltage change. It is potentially possible to utilize pressure drop signal as a diagnosis tool for stack voltage at a fixed current load. |
