IEEE Electrification Magazine - December 2013 - 58

boost converter, the voltage shape in each phase is independent of the current as the current flows over the
switch (insulated-gate bipolar transistor here) or its antiparallel diode. at the midpoint of each semiconductor leg
with respect to the midpoint across the output capacitor, a
positive or a negative voltage may be produced. therefore,
because of the two-level behavior of each semiconductor
leg, the phase of sinusoidal currents can be simply controlled. in fact, the current can be controlled to be in phase
with grid voltage for grid-to-vehicle operation or antiphase with grid voltage for V2G operation. hence, this configuration offers bidirectional operation.
the circuit in Figure 15(b) is a Vienna rectifier, which
contains only three active switches. the switching of
semiconductors is independent of the direction of phase
currents. the major advantage of the three-level
characteristic is that switches can be rated for only half of
the peak value of the line-to-line voltage. Furthermore,
because of the three voltage levels, a smaller grid current
fundamental ripple is generated, and the value of the
input boost inductances can be reduced. in addition,
because of lower switching voltages, a lower conducted
eMi noise is generated.

conclusions
although a great vision has been plotted for transportation electrification, there are several critical hurdles that
eVs must stride. among these, charging convenience and
charging time are two of the most important concerns
from the consumer perspective. Good power quality, compact size, and high conversion efficiency are three of the
most important features desired from onboard level 1 and
level 2 peV chargers. to ensure good power quality, the ac/
dc stage must be featured with good pFc and thD reduction performances. higher switching frequency, ZVS, and
advanced packaging techniques are necessary to achieve
smaller charger size. to achieve high converter efficiency,
advanced magnetics materials, power semiconductors,
and power electronic topologies must to be addressed. in
particular, the advanced control method must be implemented to optimize the conversion efficiency across the
full Soc range. Level 3 charging is able to reach a much
higher power level and is regarded as an important alternative to level 1 and level 2 onboard charging. it is essential to alleviating range anxiety issues as it allows for
long-distance travel similar to conventional ice-powered
vehicles. however, it requires an off-board charging station
and is mainly intended for commercial and public
charging stations.

Acknowledgment
this work has been sponsored partly by the national
Science Foundation Grant 1238985 and the Maryland
industrial partnerships program, which are gratefully
acknowledged.

I E E E E l e c t r i f i c ati o n M agaz ine / december 2013

For Further reading
K. S. K. Young, c. Wang, and L. Y. Wang, "electric vehicle
battery technologies," in Electric Vehicle Integration into
Modern Power Networks. Berlin: Springer, 2013, pp. 15-56.
a. Khaligh and S. Dusmez, "comprehensive topological
analysis of conductive and inductive charging solutions
for plug-in electric vehicles," IEEE Trans. Veh. Technol.,
vol. 61, no. 8, pp. 3475-3489, oct. 2012.
M. Yilmaz and p. Krein, "review of battery charger
topologies, charging power levels and infrastructure for
plug-in electric and hybrid vehicles," IEEE Trans. Power
Electron., vol. 28, no. 5, pp. 2152-2169, May 2013.
c.-Y. oh, D.-h. Kim, D.-G. Woo, W.-Y. Sung, Y.-S. Kim, and
B.-K. Lee, "a high-efficient nonisolated single-stage onboard battery charger for electric vehicles," IEEE Trans.
Power Electron., vol. 28, no. 12, pp. 5746-5757, Dec. 2013.
S. Dusmez, a. cook, and a. Khaligh, "comprehensive
analysis of high quality power converters for level 3 offboard chargers," in Proc. IEEE Vehicle Power and Propulsion Conf., 2011, pp. 1-10.
c. Botsford and a. Szczepanek, "Fast charging vs. slow
charging: pros and cons for the new age of electric vehicles," in Proc. Int. Battery, Hybrid and Electric Vehicle Symp. and
Expo. (EVS24), Stavanger, norway, May 2009, pp. 1-9.
Sae Standard for electric Vehicle conductive charge
coupler, Sae Standard 1772-2009. [online]. available:
http://www.arb.ca.gov/msprog/zevprog/stakeholders/
infrastructure/finalsaej1772.doc

IEEE Standard for Interconnecting Distributed Resources
with Electric Power Systems, ieee Standard 1547-2003, 2003.
SAE Standard for Power Quality Requirements for Plug-In
Electric Vehicle Chargers, Sae Standard J2894-2011, 2011.
IEC Standard for Line Current Harmonic Measurements, ieee Standard 1000-3-2, 1995.
NEC Standard for Compliance for Photovoltaic Systems,
U.S. national electric code (nec) Standard 690.

biographies
Haoyu Wang is a ph.D. candidate at the power electronic,
energy harvesting and renewable energies Laboratory at
the electrical and computer engineering Department in the
University of Maryland. he is a Student Member of the ieee.
Amin Hasanzadeh is a postdoctoral research associate
at the power electronic, energy harvesting and renewable
energies Laboratory at the electrical and computer engineering Department in the University of Maryland. he is a
Member of the ieee.
Alireza Khaligh (khaligh@ece.umd.edu) is an assistant
professor and the director of the power electronic, energy
harvesting and renewable energies Laboratory at
the electrical and computer engineering Department
in the University of Maryland. he is a Senior Member of
the ieee.

http://www.arb.ca.gov/msprog/zevprog/stakeholders/

Table of Contents for the Digital Edition of IEEE Electrification Magazine - December 2013