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This paper presents the optimization of the driving strategy of a high efficiency fuel cell based power train. This power train is developed to equip a light duty urban-concept vehicle that runs energetic races. The objective is to go the furthest with the lowest quantity of fuel. A comprehensive dynamical model is presented, including the mechanical requirement, the thermal behavior of the fuel cell stack and the various losses and consumptions of the power train devices. This model is next integrated into a global optimization algorithm, to determine the best race strategy to be adopted. These results are validated on experimental measurements, obtained during a real race at the Shell Eco-Marathon, in 2015.

The present paper proposes a new 2D modelling of ac impedance spectra of polymer electrolyte fuel cells (PEMFC). The computational domain includes the Membrane Electrode Assembly, the Gas Diffusion Layers and the channels on both the anode and cathode sides. The model takes into account the main fuel cell phenomena, i.e. reactants, charges transport and transfer and electrochemical reactions. First, the partial differential equations are solved in the steady state regime, then in the frequency domain in order to obtain the cell dynamic behaviour at different potentials. Experimental PEMFC impedance spectra are satisfactory reproduced over a relative large potentials range using only one set of model parameters. Numerical analysis of the key model parameters linked to the cell flooding state has been done. It is concluded that at least two impedance spectra at low and high potential are needed in order to discriminate the nature and the location of the cell degradations (anode or cathode, electrode or GDL). Based on a least square criterion, the model inversion is presented and several cell flooding scenarios have been precisely identified.