Fuel cell systems: Theory and applications

Fuel cells uses electrochemical reactions to produce energy. Because of very useful application areas, proton exchange membrane (PEM) fuel cells are the most promising fuel cell among the other types of fuel cells. PEM fuel cell uses hydrogen as a fuel and as a result of chemical reaction between oxygen and hydrogen, water and electric current is produced. In this thesis, hydrogen energy, other fuel cell types running on hydrogen energy, and challenges on commercialization of fuel cells are presented. Modelling and performance of fuel cells are presented, and also with Matlab simulation program, gross power, polarization curve and the requirement of fuel cell for oxygen, hydrogen and dry air for different current densities are simulated for a PEM fuel cell. The fuel cell system is identified for two different cases, firstly the system is identified for air and hydrogen inputs and voltage output, then for the second case the system is identified for the input is current density and the output is voltage of the cell. Identified systems are tested for different inputs and for the first case when hydrogen and air are inputs, starvation of the fuel cell is shown for different air inputs. The thesis with the presented model give a basis for the control of fuel cell systems.