Nonlinear time-variant model of the PEM type fuel cell for automotive applications

•The paper presents a control-oriented mathematical model of the PEM type fuel cell for automotive applications.•The paper proposes a more complete equivalent circuit of the PEM single cell.•Simulations of urban and highway driving cycles show that the model is suitable for control in automotive applications.•Results reveal that membrane humidity can be controlled to improve the fuel cell’s efficiency.•The model is validated by experimental tests on a 50 W PEM fuel cell.

This paper deals with nonlinear dynamic modeling of the Proton Exchange Membrane Fuel Cell (PEMFC) dedicated for automotive applications. A time-variant state space model taking into account most of internal phenomena is built. Based on electrical and diffusion approaches, the model proposes a more complete equivalent circuit including all cell components. The proposed circuit couple between gas diffusion, membrane water content, temperature, activation, ohmic and concentration losses, as well as double layer and geometrical capacitances. Similarly to engine vehicles, the model consider the hydrogen flow rate as input controlled by the pilot to change vehicle’s speed. Urban and highway driving cycles similar to those of Nissan LEAF are simulated. Simulation results show that the model responds to both low and high dynamics of power demand. Results reveal that membrane humidity has a considerable effect on the cell’s efficiency. This offer the opportunity to use the model, in a future work, to improve the fuel cell’s efficiency through the control of humidity. The model is validated by experimental tests on a 50 W PEMFC.