A Three Dimensional Electrical Model of PEMFC Stack

Mathematical modeling is an essential tool in the design of fuel cell systems, as it is important to understand the response of a stack under different conditions. This paper proposes a three dimensional electrical model of PEMFC stack. Such approach highlights the phenomena that occur at the macroscopic scale which are the electrical interactions taking place within the stack. At this scale, the microscopic phenomena are taken into account by averaging them over all the thickness of the membrane electrode assembly (MEA). This model consists of solving the charge transport equation in three dimensions. In order to avoid interfacial issues with the potential jump that occurs in the MEAs, a special source term is added in the transport equation. It makes the model robust, reliable, and helpful for understanding the effect of anomalies on the electric behavior of a PEMFC stack. After describing the equations and the numerical method used for the model, the paper shows some electrical phenomena such as cells interactions, non-equipotential bipolar plate, higher cell voltages and internal loop of current.