Methodology for readjusting the voltage according to the operating conditions of a high temperature proton exchange membrane fuel cell

High Temperature Proton Exchange Membrane Fuel Cells (HT-PEMFC) can reject very small quantities of phosphoric acid due to the ageing of their electrolyte. Also, as a preventive measure, the tests performed with this technology are often not pressure-regulated to prevent the outlet valve opening from clogging in case of acid leakage. In this configuration, atmospheric pressure variations lead to pressure changes in both fuel cell anode and cathode compartments, these pressure variations themselves generating cell voltage variations. The work presented in this article introduces a readjustment method for the fuel cell voltage according to the variations of the operating conditions. This readjustment is based on the realization of a design of experiments to characterize the voltage sensitivity to the ambient pressure and temperature of a commercial membrane electrode assembly (MEA, BASF Celtec®-P 1100W type). An empirical model is identified from these experimental data obtained. It is then used to generate the compensating coefficients to smooth the impact of variations in operating conditions. Finally, the readjustment method is applied and discussed to the fuel cell voltage for a test example.