Exploiting Vector Extremum Seeking Control for Simultaneous Optimization of Net Power and Lifespan Enhancement of PEM Fuel Cells

In many real world problems, it is needed to solve an online optimization problem to achieve a certain criteria. One of the practical tools for online optimization is extremum seeking control. The main disadvantage of this method is its weakness in dealing with multi variable optimization problems. The vector extremum seeking control technique overcomes this weakness and is able to determine several variables for online optimization of a performance function. This paper uses the vector gradient based extremum seeking control technique to optimize the net power (the produced power minus the used power) in the Proton Exchange Membrane Fuel Cell (PEMFC) while the PEMFC lifespan is enhanced. The net power optimization is achieved by controlling the oxygen flow and the lifespan enhancement is obtained by controlling the inlet hydrogen flow which keeps the pressure difference of cathode and anode close to zero. The controller performance is investigated by simulating it on a sample PEMFC model. The simulation results indicate that the partial pressure difference of cathode and anode is close to zero and the PEMFC net power is optimized at the same time. The controller increases the net power up to 20 percent.