Power tracking for PEM fuel cell engine based on optimal oxygen excess ratio

Generally, automobiles are subjected to significant load transitions during operation and the fuel cell system should be able to produce power which can follow this time varying load profile. In this paper, a two-freedom PID controller (master controller, MC) combined with a feed-forward and PID controller (slave controller, SC) are proposed here to cope with the power tracking problem, furthermore, it can also keep the FCE (Fuel cell engine) under the optimal oxygen excess ratio. Finally, the simulations are conducted both for the FCE with the normal model and uncertain model (i.e. the model with 20% power decay).