Integrated chargers
for EVs
I. Subotic, N. Bodo, E. Levi
The FUTURE and VESI seminar
Shard, London
14th January 2015
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Presentation outline:
•
•
•
•
Introduction
Demonstrator 3 aims
Three-phase charging
Single-phase charging
1) Introduction
machine
ac/dc
battery
1) Introduction
charger
machine
ac/dc
battery
1) Introduction
machine
ac/dc
battery
1) Introduction
machine
ac/dc
battery
2) Demonstrator 3 aims
9-phase machine
battery
2) Demonstrator 3 aims
9-phase converter
control panel
2) Demonstrator 3 aims
microcontroler unit
GUI
3) Three-phase charging
9-phase inverter
3-phase
grid
9-phase
machine
ic
iag /3
vag iag
+
iag /3
iag /3
ibg /3
vbg
+
ibg
ibg /3
ibg /3
icg /3
vcg icg
+
dc-dc converter
idc
icg /3
icg /3
va
vd
vg
vb
ve
vdc
C
iL
vh
vc
vf
BAT
vi
Integrated propulsion/charging topology
3) Three-phase charging
9-phase inverter
3-phase
grid
9-phase
machine
ic
iag /3
vag iag
+
iag /3
iag /3
ibg /3
vbg
+
ibg
ibg /3
ibg /3
icg /3
vcg icg
+
dc-dc converter
idc
va
vd
vg
vb
ve
vdc
iL
C
vh
vc
icg /3
vf
icg /3
BAT
vi
Integrated propulsion/charging topology
idc
3-phase 9-phase
grid machine
vag
+
vbg
+
vcg
+
Lf, Rf iag va
Lf, Rf ibg
iL
ic
vb
Lf, Rf icg
equiv. circuit
vdc
vc
C
BAT
3) Three-phase charging
Charging mode
• In charging mode it can
be seen that the
current is in phase with
the grid voltage, which
confirms unity power
factor operation.
• Spectrums of grid and
machine current show
very small low-order
harmonics in both
charigng and V2G
mode.
V2G mode
3) Three-phase charging
Charging mode
• There is no excitation
in the first plane of the
machine, which
confirms that a torque
is not produced during
the charging/V2G
process.
• Excitation maps into
the second plane and
in zero-sequence.
V2G mode
3) Three-phase charging
Charging mode
• The grid current qcomponent is kept at
zero, while the dcomponent is used for
energy transfer.
• Machine does not
rotate during the
charging/V2G process.
• Transient from
charging into V2G
mode of operation is
fast.
V2G mode
4) Single-phase charging
single-phase
grid
i+g
+
vg
i-g
i=0
9-phase machine
9-phase inverter
i+g /3
ia
i+g /3
id
i+g /3
ig
i-g /3
ib
i-g /3
ie
i-g /3
ih
i=0
ic
i=0
if
i=0
ii
dc-dc converter
idc
ic
va
vd
vg
vb
ve
vh
vdc
vc
vf
iL
C
vi
BAT
Integrated propulsion/charging topology
idc
single-phase
grid
i+g
+v
g
multiphase
machine
Lf, Rf
i+g
i-g
iL
ic
vset1
vset2
equiv. circuit
vdc
C
BAT
4) Single-phase charging
Charging mode
• Again unity power
factor is accomplished
in both charging and
V2G mode.
• Grid and machine
curents spectrums
demonstrate excellent
current quality with
low order harmonics
below 1% of the
fundamental.
V2G mode
4) Single-phase charging
V2G mode with interleaving
• It can be seen that the
interleaving process
singnificantly reduces
grid current ripple.
• On the other hand,
interleaving process
increases machine
current ripple
• Transient from V2G
into the charging mode
is almost
instantaneous.
V2G mode
Experimental rig
grid
9-phase
machine
9-phase
converter
dc voltage
source
resistor
load
dSPACE
Conclusions
• Since in EVs propulsion and charging power-electronics components are never used
simultaneously they can be replaced with a single component that is capable of
performing both functions. The process is called integration and it has many benefits.
• The major obstacle against integration of a three-phase machine is torque production.
Demonstrator 3 presents fully integrated nine-phase topology that does not have
torque production during the charging/V2G mode. Moreover, it does not require any
hardware reconfiguration between charging/V2G and propulsion mode of operation. It
is capable of charging from both three-phase and single-phase grid.
• Experimental rig is developed. Preliminary experimental results demonstrate unity
power factor operation in both three-phase and single-phase charging/V2G mode.
Control achieves currents with excellent quality. A torque is not produced in the
machine during the experiments.
Thank you
Contact details:
i.subotic@2011.ljmu.ac.uk
n.bodo@ljmu.ac.uk
e.levi@ljmu.ac.uk