Reliability computing of polymer-electrolyte-membrane fuel cell stacks through Petri nets

In this paper a model is introduced which computes reliability data of PEMFC (polymer-electrolyte-membrane fuel cell) stacks, especially the average lifetime of a single stack or the reliability of stacks of a whole fuel cell vehicle fleet within a given timing. The stack and its behaviour over time is modelled by a Petri net. The behaviour is divided into degradation, spontaneous and reversible events. Through the worsening over time the characteristics voltage, internal and external leakages, which are assigned to the components MEA (membrane electrolyte assembly) and BIP (bipolar plate), are changed. Thresholds for every characteristic monitor the operating ability of the whole stack.