Experimental tests on dynamic behaviour of a PEMFC stack

At Dept, of Industrial Engineering (DII) a test system for PEMFC stacks has been engineered and experimental tests have been carried out. The power of the stack currently installed is I. I kW, but the test system is able, with few changes, to test stacks up to 30 kW.
A first experimental phase was devoted to characterise the stack static behaviour with concern to voltage and efficiency versus current density. In this paper we discuss the second experimental phase, i.e. tests carried out in order to investigate the dynamic stack behaviour due to a load fast variation.
The tests were carried out in a "laboratory" at open air because the goal was to investigate the stack behaviour in almost real operating conditions.
Although load transients are present both in the voltage and current generated, the results obtained have pointed out that the stack current and voltage response is adequate as the transient phenomena generally end in few seconds.