Abstract: According to the status in the vehicle, a low pressure vehicle proton exchange membrane fuel cell (PEMFC) stack model is developed using a semi-empirical modeling technique. First, the oxygen concentration item is derived from the PEMFC output voltage equation, and the concept of oxygen concentration resistance coefficient is presented. Secondary, the ohm losses in many different temperatures are determined via the experiments with the current interrupt method, which is formulized with linear regression method. Then, the oxygen concentration item is studied by the experiments with different air stoichiometric ratios while keeping the other operating parameters unchanged, and the oxygen concentration resistance coefficient is obtained by the genetic arithmetic which is used to process the difference voltages of the PEMFC stack in different air stoichiometric ratios. Then, the activation loss is obtained based on PEMFC output voltage and the loss of ohm and the loss of concentration. Finally, with the correlation of the model to 20 actual experimental data, the good agreement between the computation results and the experimental results is found out. The credibility of the modeling method is verified and the precision of the model is in accord with the systematic optimization and control.

Key words: Concentration resistance coefficient, Modeling, Ohm loss, Proton exchange membrane fuel cell stack, corrosion, cyclic-immersion corrosion test, electrochemistry, tidal zone, Q345D low alloy steel