Mathematical modelling and dynamics of proton exchange membrane electrolyzer

Proton exchange membrane electrolyzer has emerged as a capable energy source and is a primary building block in delivering clean energy solutions. This work proposes a comprehensive model of a proton exchange membrane electrolyzer-based hydrogen generating system using MATLAB/Simulink environment. The proposed model incorporates key variables such as membrane water content, mass conservation, and thermodynamic principles. A step change in current from 40A to 15A is introduced to show the formulated model's flexibility, capturing the dynamics of partial pressure, voltage, and hydrogen produced. A drop in cell voltage from 1.65 V to 1.39 at 0.5A/ cm2 is observed when the temperature is increased from 280K to 360K, proving the model's accuracy. The results also showed that voltage losses are due to activation, concentration, and electronic and ionic ohmic losses at varying current densities. Moreover, the numerical study of this model is validated with experimental investigation, resulting in the root mean squared error of 0.012.