Moreover, these models can easily incorporate the anisotropic material properties of various cell layers, which is especially important in the case of gas diffusion layers (GDLs).
On the other hand, these models are computationally very expensive and do not lend themselves to real-time applications.
Furthermore, it requires extensive parameter identification to fit the modeling results to experimental data.
Nevertheless, it remains one of the main models that is used in the control community. proposed a reduced model for nonlinear model predictive control applications, where they used representative elementary volumes (REVs) to reduce partial differential equations (PDEs) into ordinary differential equations (ODEs).
These studies suggest that fast dynamics of gas transport in the fuel cell can be neglected with relatively small errors when time scales of larger than 10 milliseconds are of interest.
In terms of reaction kinetics, the Butler-Volmer (BV) equation is traditionally used to describe activation overpotentials on both anode and cathode electrodes.
Order of magnitude analysis has been reported in the literature to show the time constants associated with various dynamics in the cell. presented such an analysis, where they found the time constants for gas diffusion in porous media and reaction kinetics to be on the order of a few milliseconds.
They also associated a time constant of 2 × 10 where they also found the dynamics associated with gas species diffusion to be very fast compared to other transients.
As mentioned earlier, including all these effects results in increased computational costs, whereas lower costs are desired for real-time applications.
To this end, many computationally efficient models have been proposed in the literature. developed a 0-D isothermal and dynamic model for system-level control tasks.