Estimation of water content in PEM fuel cell

The Polymer electrolyte membrane fuel cell (PEMFC) is a high potential alternative energy to apply for the automotive application due to its advantages such as clean energy source and compact size. To achieve high performance, the amount of water content in PEMFC should be in the suitable range that is adequate to hydrate membrane but not disturb the transportation of the reactant gas. Because of the difficulty to monitor the water content in PEMFC and limitation of the hardware installation, this research proposed the new technique to predict the water content in PEMFC via the state estimation. The concept of extended Luenberger observer is applied to estimate the water content. The membrane water content is calculated from the relation of membrane resistance and the amount of water in each channel is calculated from the mass balance. The simulation results of proposed method compared with that of open-loop observer are presented. From the simulation, the extended Luenberger observer can eliminate the offset while the open-loop observer can not.