IEEE Electrification Magazine - December 2014 - 12

The electrical
system is used
to power loads
such as the avionics
systems, lighting,
and in-flight
entertainment.
as well as the low-frequency power quality. Models at this
layer are based on nonswitching averaged models of equipment. Simulation studies at this layer are capable of running at near-real-time speeds and so the behavior of the
electrical system during flight profiles can be performed.
Figure 8 shows a typical comparison between the
behavioral and functional level models. This example is
for the loss of one generator and the subsequent reconfiguration of the electrical system, as shown in Figure 3.
The fictional model accurately captures the transient
activity of the system variables, but the behavioral model
also captures the high-frequency switching components
in the waveforms.
The architectural layer is used for top-level global electrical power system architecture studies. The architectural
layer does not model transient dynamics, but considers
the global system in steady state. The main use of models
in this layer is for sizing and system-level design.

conclusion
This article has introduced some of the solutions and technologies being developed for the More Electric Aircraft. The

vhvac (V)

400
300
200
100

Behavioral
Functional

0
1.195 1.2 1.205 1.2 1.215 1.2 1.225 1.23 1.235 1.24
(a)

vhvac2 (V)

340
320
300
280

Behavioral
Functional

1.195 1.2 1.205 1.2 1.215 1.2 1.225 1.23 1.235 1.24
(b)
Figure 8. The transient response of VHVAC1 and VHVAC2 on SG1 loss.

I E E E E l e c t r i f i c ati o n M agaz ine / december 2014

article has considered power generation, typical loads, and
electrical actuation systems as well as electrical power system voltage and frequency. These technologies have the
potential to make a relatively small improvement in the
overall efficiency of an aircraft, but this efficiency savings
will result in a massive savings in fuel costs over the life of
an aircraft and a considerable reduction in emissions from
air travel.

Acknowledgments
We would like to acknowledge the funding through the
European Union-funded Clean Sky JTI project, which made
this work possible as well as the contribution to this work
of many members of the Power Electronics, Machines, and
Control Group at the University of Nottingham.

Further reading
K. Karimi, "Role of power electronics in more-electricairplanes," in Proc. European Power Electronics Conf., U.K.,
Sept. 2011, pp. 49-54.
I. Moir, "More-electric aircraft-system considerations,"
in Proc. IEE Colloqu. Electrical Machines and Systems for the
More Electric Aircraft, 1999, pp. 10/1-10/9.
P. Wheeler, "The More Electric Aircraft-The importance of
power electronics," in Proc. European Power Electronics Conf.,
Spain, Sept. 2009, pp. 201-206.
T. Jomier, "More open electric technologies-Final
report," EU FP6 Project Rep., Dec. 2009.

biographies
Pat Wheeler (Pat.wheeler@nottingham.ac.uk) is a professor of power electronic systems and director of the
Institute of Aerospace Technology at the University of
Nottingham, United Kingdom.
Sergei Bozhko (serhiy.bozhko@nottingham.ac.uk) is a
principle research fellow in the Power Electronics,
Machines, and Control Research Group at the University of
Nottingham, United Kingdom.

Table of Contents for the Digital Edition of IEEE Electrification Magazine - December 2014