Variable Parameters Model of a PEM Electrolyzer Based Model Reference Adaptive System Approach

This paper proposes an equivalent circuit model of a PEM electrolyzer in which the time constant of the cathode reaction depends on the current supplied to the electrolyzer. A fixed-parameter circuit model is used to implement an analytical impedance function in which the time constant is identified based on the error between the output voltage given by the model and the voltage at the terminals of the electrolyzer. The identification is performed by using experimental data when supplying the electrolyzer with different current steps. The developed model is validated by using a commercial-400 W PEM electrolyzer. The obtained results allow demonstrating the effectiveness of the adaptive system approach to estimate the time constant of the cathode reaction.