IEEE Electrification Magazine - December 2017 - 84

Load Power
Ultracapacitor Power
Fuel Cell Power

Power (kW)

-2

Load Power
Ultracapacitor Power
Fuel Cell Power

100

200
Time (s)
(a)

300

400

-2

100

200
Time (s)
(b)

300

400

Figure 19. Power sharing achieved via an experiment with an actual fuel cell: (a) a bus managed by the fuel cell (strategy one); (b) a bus managed by the stored energy (strategy two).

Tests with an Actual Fuel Cell
The tests in Figure 15 were repeated with the real fuel cell
stack, the characteristics of which are given in the
"Description of the Experiment Performed" section.
Figure 19 shows the hybridization tests with the fuel cell
stack for both strategies put forward in this article.
The same phenomena as in Figure 15 can be seen, with one
less high-frequency undulation because a significant part
of the high-frequency part present at the power supplied by
the fuel cell emulator was due to the three-phase electrical
network. As the fuel cell is a dc source, these undulations
no longer appear. However, even more harmonics provided
by the fuel cell are found in strategy one for the same reasons as in the "Emulation of a Fuel Cell" section, i.e., a
stored energy converter that is less dynamically effective
than the fuel cell converter.

Conclusions
Going from simulation to experiment confirmed the theoretical results but also revealed phenomena that were not
apparent during the simulations (e.g., interference between
the converters, voltage rise of the elements, connections
between them, immunity to noise, resonance, and so forth).
In addition, while Figures 10 and 19 are relatively similar, we
can see that the mean current provided by the fuel cell during the simulations (Figure 5) is higher than that observed in
the experiment. This is due to the ultracapacitor technology,
which had developed in the meantime (the internal resistance is now lower than during the theoretical study), but is
also due to the scale factor, which considered the losses to
be greater in the more powerful converters. However, the
emulation showed very satisfactory results with respect to
the experiment with an actual fuel cell, confirming all of the

I E E E E l e c t r i f i cati o n M a gaz ine / DECEMBER 2017

potential offered by fuel cell emulation (e.g., to go toward full
scale in terms of power). This work was continued by replacing the ultracapacitors with a battery for different aviation
specifications ( Jaafar et al. 2014).

Acknowledgments
The authors would like to thank France's General Directorate for Civil Aviation for funding this article as part of the
ISS Power and Control project led by Airbus. This study
was conducted in partnership with Airbus and the AKKA
Technologies Group.

For Further Reading
J. A. Weimer, "Electrical power technology for the more electric aircraft," in Proc. 12th AIAA/IEEE Digital Avionics Syst. Conf.,
Oct. 1993, pp. 445-450.
X. Roboam, B. Sareni, and A. D. Andrade, "More electricity
in the air: Toward optimized electrical networks embedded in
more-electrical aircraft," IEEE Ind. Electron. Mag., vol. 6, no. 4,
pp. 6-17, 2012.
J. A. Rosero, J. A. Ortega, E. Aldabas, and L. Romeral, "Moving
toward a more electric aircraft," IEEE Aerosp. Electron. Syst.
Mag., vol. 22, no. 3, pp. 3-9, Mar. 2007.
I. S. Mehdi and E. J. Woods, "Electrical power systems for
high mach vehicles," in Proc. IEEE Energy Conversion Engineering
Conf., Washington, DC, 1989, pp. 625-630.
P. Bolognesi, F. Papini, and L. Taponecco, "Hybrid-excitation
dc machines as highly reliable generators for ram air
turbines," in Proc. IEEE Industrial Electronics Society Conf., Porto,
Portugal, 2009, pp. 2569-2574.
D. Van Den Bossche, "More electric control surface actuation: A standard for the next generation of transport aircraft,"
in Proc. 10th European Power Electron. and Applicat. Conf., Toulouse, France, 2003, pp. 1-6.
M. Garcia-Arregui. (2007). Theoretical study of a power
generation unit based on the hybridization of a fuel cell stack
and ultracapacitors. Ph.D. dissertation, Institut. Nat. Polytech.,

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