**5. Conclusions**

in this work.

**5. Conclusions** The fuel cell is an electric component that is used more and more in distributed generation power fields, but also in hybrid electric vehicles. Its modelling is an important step not only to understand its dynamic behaviour, but also to develop advanced controllers for systems based on the fuel cell. Several models are proposed in the literature; this work re-investigates some of these most common models. The study shows that the equivalent electric RC circuit is not appropriate, since it presents a different behaviour from the experimental results. Therefore, the paper presents an analysis of a new equivalent electric RL circuit. A comparative study of different models with experimental data The fuel cell is an electric component that is used more and more in distributed generation power fields, but also in hybrid electric vehicles. Its modelling is an important step not only to understand its dynamic behaviour, but also to develop advanced controllers for systems based on the fuel cell. Several models are proposed in the literature; this work re-investigates some of these most common models. The study shows that the equivalent electric RC circuit is not appropriate, since it presents a different behaviour from the experimental results. Therefore, the paper presents an analysis of a new equivalent electric RL circuit. A comparative study of different models with experimental data from a Nexa 1200 PEMFC reveals the advantages and disadvantages of each model. It turned out that

from a Nexa 1200 PEMFC reveals the advantages and disadvantages of each model. It turned out that the mathematical nonlinear model is better than the other investigated

real-time application and control purposes. The classic RC model and the proposed RL model have practically the same RMSE in static conditions. Nevertheless, the proposed equivalent electric RL model presents the advantages of providing the best transient behaviour compared to the classic RC model; indeed, contrary to the investigated models, the advantage of the proposed equivalent RL model lies essentially in its simplicity, and its ability to produce a transient behaviour similar to that of the commercial fuel cell used

**Author Contributions:** Conceptualization, H.E.F.; Formal analysis, F.Z.B.; and H.E.F.; Resources, M.K.; Software, .Z.E.I.; Supervision, F.G.; Writing—review & editing, A.I. All authors have read

**Acknowledgments:** The authors gratefully acknowledge the support of the Moroccan Ministry of

**Funding:** This research was funded by the CNRST under grant number PPR/2015/36.

Higher Education (MESRSFC) and the CNRST under grant number PPR/2015/36.

and agreed to the published version of the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest

the mathematical nonlinear model is better than the other investigated models, but requires a longer computational time, which is considered a drawback for real-time application and control purposes. The classic RC model and the proposed RL model have practically the same RMSE in static conditions. Nevertheless, the proposed equivalent electric RL model presents the advantages of providing the best transient behaviour compared to the classic RC model; indeed, contrary to the investigated models, the advantage of the proposed equivalent RL model lies essentially in its simplicity, and its ability to produce a transient behaviour similar to that of the commercial fuel cell used in this work.

**Author Contributions:** Conceptualization, H.E.F.; Formal analysis, F.Z.B.; and H.E.F.; Resources, M.K.; Software, Z.E.I.; Supervision, F.G.; Writing—review & editing, A.I. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the CNRST under grant number PPR/2015/36.

**Acknowledgments:** The authors gratefully acknowledge the support of the Moroccan Ministry of Higher Education (MESRSFC) and the CNRST under grant number PPR/2015/36.

**Conflicts of Interest:** The authors declare no conflict of interest.
