Temperature and Humidity Control of a Micro PEM Fuel Cell Stack

This paper deals with the control of a miniaturized fuel cell system. A single air blower is used to control both heat and water management of the fuel cell. As the number of manipulated variables is smaller than the number of control variables, classical control algorithms are not applicable. To find a suitable controller, a system model is developed that shows the qualitatively same behavior as the experimental setup. The dynamic behavior of the model and the influence of the blower are studied by phase portraits. A control algorithm is then conceived by qualitative analysis of the phase portraits and tested in simulations.