Low pressure PEM electrolyzer system modeling with heat loss representation

Abstract

• Modeling of Low Pressure PEM Electrolyzer System • PEM electrolyzer stack containing 15 cells arranged in series with a power of one kW. • Recursive identification algorithm • Nonlinear least squares algorithm. Low-pressure proton exchange membrane (PEM) electrolyzers are increasingly recognized for their effectiveness in hydrogen production, especially when combined with renewable energy sources. These systems function efficiently at reduced pressures, leading to lower cost of operation and improved safety. A mathematical model is developed for the PEM electrolyzer to enhance the prediction of the system's behavior and output parameters, accompanied by a brief description of the assumption to simplify the model. The simulation is performed utilizing MATLAB/Simulink software package to compute and plot the necessary output parameters, thereafter, comparing the results with data acquired from a practical electrolyzer. By comparing the simulation results along with the data of a commercial electrolyzer, the findings show that the minimum error of 2 %. For more flexibility, the simulation includes the capability to change simulation parameters. This option facilitates various results and graphs, while providing additional insight into system performance and the identification of calculation errors. Also, the manuscript provides an engineering practical modelling for the PEM electrolyzer, that takes into consideration heat losses from gases and pipelines. A recursive identification algorithm method is utilized to estimate the additional resistance associated with heat loss. The value is based on the relationship between the current and the heat loss for the identification of the engineering circuit model. The root mean square error (RMSE) between the identification results of the engineering model and the simulation results is 0.454%. MATLAB programming is used to develop the model and evaluate the accuracy of the proposed identification method.