This work presents a nonsmooth adaptive extremum seeker that minimizes the hydrogen consumption in a fuel cell system. The extremum seeker operates by estimating the gradient of the objective function but, unlike other seekers, it does not require a dither signal to produce such estimate. The absence of a dither signal simplifies the choice of parameter values for the seeker and, more importantly, it allows it to converge to the optimal value exactly, not only to a small neighborhood. The proper functioning of the proposed scheme is proved using nonsmooth Lyapunov analysis. The strategy is tested on the input–output map of a real PEM fuel cell.


control theory.

Author keywords

extremum seeking, fuel cells, nonsmooth Lyapunov analysis

Scientific reference

F. Castaños and C. Kunusch. Dither-less extremum seeking for hydrogen minimization in PEM fuel cells. IEEE Transactions on Industrial Electronics, 62(8): 5218-5226, 2015.