This work proposes a state observer as a tool to manage cost and durability issues for PEMFC (Proton Exchange Membrane Fuel Cell) in automotive applications. Based on a dead-end anode architecture, the observer estimates the nitrogen build-up in the anode side, as well as relative humidities in the channels. These estimated parameters can then be used at fuel cell management level to enhance the durability of the stack. This observer is based on transport equations through the membrane and it reconstructs the behavior of the water and nitrogen inside the channels without the need of additional humidity sensors to correct the estimate. The convergence of the output variables is proved with Lyapunov theory for dynamic operating conditions. The validation is made with a high-fidelity model running a WLTC (Worldwide harmonized Light vehicles Test Cycle). This observer provide the average values of nitrogen and relative humidities with sufficient precision to be used in a global real-time control scheme.

International audienceA Proton Exchange Membrane Fuel Cell (PEMFC) needs an active system to control all the ancillaries and ensure optimal operating conditions, especially in a fuel cell vehicle. For the fuel cell system architecture, dead-end anode is the cheapest architecture for the hydrogen line and also the one that leads to important reversible and irreversible degradations if not appropriately managed. To address the cost and durability issues on fuel cell vehicles, this study proposes a state observer which aims at estimating online the nitrogen saturation in the anode side in order to trigger the purge at a given criterion. This observer is based on a simple set of equations extracted from a detailed 2D-meshed model. Nitrogen buildup is evaluated in simulation with different road profiles with less than 5% error. Moreover the fuel cell system efficiency increases compared to the other existing purge strategies, so as the mileage. The observer can also be used to develop other optimal strategies to minimize the irreversible degradations of the fuel cell