Harmonic Analysis of a PEM Fuel Cell with a Pulsed Load Applied

The analysis of the harmonic behavior of a PEM fuel cell operating with a pulsed load is presented. A correlation between low frequency pulses and additional harmonics in the frequency spectrum of the fuel cell current is observed. The amplitudes of certain harmonics from the PEM fuel cell - pulsed load system vary significantly compared to the amplitudes of the same harmonics when the load is supplied by a DC power supply. It is shown through experimental tests on a Horizon H-100 PEM fuel cell that the 120 Hz frequency component of the fuel cell current has the potential to be used as a detector of abnormal fuel cell operation. The results from the experimental tests are presented to illustrate the behavior of the H-100 fuel cell with pulsed loads applied at various switching frequencies.