Effect of a Ripple Current on the Efficiency of a PEM Electrolyser

The aim of this study was to determine how the efficiency of a proton exchange membrane (PEM) electrolyser is affected by an electric ripple current and the different characteristics of the ripple current (frequency, amplitude and waveform). This paper presents the experimental method and measured results, used to analyse the effect of ripple currents at various frequencies, ripple factors and waveforms on the hydrogen production, power consumption and efficiency of a PEM electrolyser. An active laboratory-size PEM electrolysis system was used to investigate the impact of various ripple currents on the efficiency of the system. The results revealed that the average power consumption increases as the ripple factor increases and decreases as the frequency of the ripple increases, while the waveform of the applied current has no effect. Furthermore, the average hydrogen flow rate is unaffected by the ripple factor, frequency or waveform of the applied ripple current.