Control and optimization in fuel cell systems

Fuel cells are electrochemical energy converters. They convert the chemical energy contained in the fuel into electricity while producing water and heat. Compared to the traditional energy converters, such as batteries and internal combustion engines, fuel cells are marked by high conversion efficiency and very low emissions.This work contains a computer study of optimization and control of fuel cells systems. An analytical study of the fuel (Hydrogen and air) supply system was performed taking into account compressor, cooling and humidification subsystems. In addition, the stack system, which consists of a lot of cells, was analyzed using the experimental equations of Nafion 117 membrane. The model of the whole system was then implemented in MATLAB/Simulink environment. The effect of the cathode pressure and the membrane water content on the polarization curves of the cell was examined. To validate the model, the responses of the model to step changes in the compressor voltage and the current drawn from the stack, were used. More attention was given to the net power which can be provided by the system, taking into account the power wasted by the compressor. (author)