Approach to Meet an Overall Transient Performance Criterion of a PEM Fuel Cell System

Fuel Cells have been intensely researched and developed in the recent decade, where especially the fuel cell MEA (Membrane Electrode Assembly) and stack have been the main focus. Now the system control components surrounding the fuel cell have been given more attention. This paper gives a novel system approach of setting up the demands for control components such as valve actuators for a PEM (Proton Exchange Membrane) fuel cell system in order to meet an overall transient system performance criterion. Overall control considerations are treated, and the major time constants of the sub-systems are analyzed. The result is a method for specifying dynamic performance criteria for the individual control components. By proper selection of the components it can be shown that the electric load buffer may be omitted due to the internal capacitance of the fuel cell. Test results from a 2.5 kW PEM fuel cell test facility show close agreement with simulation results from the novel system approach.