The development and validation of a control-oriented dynamic thermal model for a polymer electrolyte membrane (PEM) fuel cell stack is presented. This model is based on the first law of thermodynamics within four defined control volumes in the fuel cell; the cathode channel, anode channel, coolant channel, and fuel cell stack body. Energy and mass conservation equations are developed for each control volume. Transient dynamics captured by this model include the electrochemical reaction, heat transfer and mass transport. Activation, ohmic, and concentration voltage losses are also modeled to improve the accuracy of the voltage model response. This allows the stack voltage and cell temperature to be modeled based on the inlet temperature, pressure, and species flow rate and the relative humidity level setting.
An experiment was conducted to give a baseline with which to tune the model. Tuning of the model parameters was performed and validation of these adjustments was then conducted through comparison to another experiment. The model predicts the dynamic thermal and electrical response of the fuel cell system with a good degree of accuracy in both cases.