Dynamic modelling of PEM fuel cells using the FuelCell Lib Modelica library

FuelCell Lib is a free Modelica library for 1D dynamic modelling of PEMFC (proton exchange membrane fuel cells). FuelCell Lib models describe the physical--chemical phenomena that take place in the cell cathode and the membrane, including the electrochemical reactions in the catalytic layer, the electron conduction in the catalytic and diffusion layers, the proton conduction in the proton conductor material (e.g. Nafion polymers) of the catalytic layer and the membrane, the coexistence of steam and liquid water, the transport of water in liquid and steam phases, the electro-osmotic drag, the transport of oxygen in steam phase in the catalytic and diffusion layers, the cathode flooding, the membrane drying and the double-layer pseudo-capacitance. The first version of FuelCell Lib was released in 2005. The second version of the library, released in 2008, is presented in this article. The modelled phenomena, modelling hypotheses and equations, the library structure and its validation are discussed. Two different validation studies of FuelCell Lib PEMFC models have been successfully completed. First, the effect on the simulated cell behaviour of selected electrochemical parameters and operating conditions has been qualitatively analysed, being the obtained results in good agreement with the results reported by other authors. Second, FuelCell Lib cell models have been validated using experimental data. The GAPILib Modelica library has been used to fit the PEMFC models to experimental data and to estimate the value of the cell model parameters. FuelCell Lib and GAPILib can be freely downloaded from http://www.euclides.dia.uned .es/