Inter
national
J
our
nal
of
Electrical
and
Computer
Engineering
(IJECE)
V
ol.
10,
No.
5,
October
2020,
pp.
5058
5073
ISSN:
2088-8708,
DOI:
10.11591/ijece.v10i5.pp5058-5073
r
5058
Har
v
esting
in
electric
v
ehicles:
Combining
multiple
po
wer
tracking
and
fuel-cells
J
uan-Gerardo
P
arada-Salado
1
,
Luis-F
er
nando
Gaona-C
´
ardenas
2
,
Mart
´
ın-Antonio
Rodr
´
ıguez-Licea
3
,
Francisco-J
a
vier
P
er
ez-Pinal
4
1,2,4
Instituto
T
ecnol
´
ogico
de
Celaya,
Departamento
de
Ingenier
´
ıa
Electr
´
onica,
M
´
exico
3
CON
A
CYT
-Instituto
T
ecnol
´
ogico
de
Celaya,
Departamento
de
Ingenier
´
ıa
Electr
´
onica,
M
´
exico
Article
Inf
o
Article
history:
Recei
v
ed
Mar
19,
2020
Re
vised
Apr
12,
2020
Accepted
Apr
23,
2020
K
eyw
ords:
Circuit
design
Electric
v
ehicle
Ener
gy
harv
esting
Ener
gy
management
strate
gy
P
arallel
DC-DC
con
v
erter
ABSTRA
CT
Exploitation
of
green
ener
gy
sources
is
essential
to
diminish
the
de
terioration
of
our
en
vironment.
The
ener
gy
harv
esting,
represents
an
alternati
v
e
to
achie
v
e
greater
range
in
electric
and
h
ybrid
v
ehicles.
An
ener
gy
management
strate
gy
(EMS)
must
be
optimized
to
obtain
the
best
benefits
in
such
v
ehicles,
which
is
not
a
tri
vial
task.
If
harv
esting
or
ener
gy
reco
v
ery
de
vices
ar
e
added,
the
EMS
becomes
a
dual-purpose
algorithm:
minimizing
fuel
consumption
and
maximizing
ener
gy
harv
est
through
maximum
po
wer
point
tracking
(MPPT)
controllers.
Kno
wn
studies
consider
separate
EMS,
one
for
traction
and
another
for
re
generati
v
e
braking,
without
considering
harv
est
de
vices
such
as
solar
panels,
re
generati
v
e
suspensi
on,
thermal
generators,
among
others.
Furthermore,
the
electronic
po
wer
con
v
erter
s
used,
are
not
designed
to
handle
such
unequal
po
wer
le
v
els.
In
this
article,
an
electronic
platform
to
include
multiple
ener
gy
harv
esting
de
vices
in
a
fuel-cell
h
ybrid
electric
v
ehicle,
w
as
presented
together
with
a
multiple
MPPT
-EMS.
The
EMS
is
easily
implementable,
and
considers
quasi-constant
cell
ener
gy
e
xtraction
and
filtering
of
current
transients
t
o
the
battery
bank
ensuring
the
longe
vity
of
the
de
vices.
A
ne
w
mathematical
model
of
the
platform,
a
closed
loop
stability
analysis,
and
numerical
and
Hardw
are-in-the-Loop
(HIL)
v
alidations
were
presented.
Some
e
xperimental
v
alidation
results
were
also
pro
vided.
Copyright
©
2020
Insitute
of
Advanced
Engineeering
and
Science
.
All
rights
r
eserved.
Corresponding
A
uthor:
Mart
´
ın-Antonio
Rodr
´
ıguez-Licea,
Departamento
de
Ingenier
´
ıa
Electr
´
onica,
CON
A
CYT
-Instituto
T
ecnol
´
ogico
de
Celaya,
Antonio
Garc
´
ıa
Cubas
600,
F
o
vissste,
38010
Celaya,
Guanajuato,
M
´
exico.
T
el:
+52-461-611-7575
Email:
martin.rodriguez@itcelaya.edu.mx
1.
INTR
ODUCTION
No
w
adays,
the
importance
of
migrating
mobility
to
greener
en
vironments
and
inte
grating
it
into
the
electric
netw
orks
is
well
kno
wn,
due
to
the
impending
deterioration
of
the
planet
[1].
Unfortunately
,
for
pri
v
ate
mobility
,
electri
c
v
ehicles
(EV)
are
not
yet
a
viable
option
for
the
a
v
erage
consumer
for
tw
o
reasons,
their
high
cost
and/or
their
lo
w
range
(miles
per
char
ge)
with
respect
to
int
ernal
comb
ustion
v
ehicles
[2].
W
ide
range
and
lo
w
cost
are
v
ariables
closely
related
to
the
capacity
of
the
BB
used
in
EV
and
alternati
v
es
are
currently
being
sought;
one
of
these
alternati
v
es,
is
the
inte
gration
of
po
wer
generati
ng
sources
to
maintain
and
e
v
en
raise
the
state
of
char
ge
(SoC)
while
the
EV
circulates
[3],
such
as
solar
panels
[4–7],
h
ydrogen
fuel
cells
(HC)
[8–13],
biofuel
engines
[14,
15],
h
ybrid
motorization
[16,
17],
electric
generating
dampers
[18–23],
wireless
rechar
ge
[24,
25],
among
others.
Unfortunately
,
the
combined
and
simultaneous
use
of
ener
gy
sources
in
EVs
has
been
studied
only
for
particular
cases
(do
not
consider
se
v
eral
ener
gy
harv
esting
possibilities
together
with
HC,
BB
and
SC)
J
ournal
homepage:
http://ijece
.iaescor
e
.com
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5059
or
it
is
not
considered
that
the
BB
and
the
HC
can
de
grade
under
conditions
of
o
v
erload
or
current
demand
transients
[26–29].
In
[30]
the
authors
considered
A
C
(kinetic
ener
gy
,
motion
or
electromagnetic
radiation)
and
DC
(thermal
or
solar)
harv
est
de
vices/collectors;
their
proposed
ener
gy
management
strate
gy
(EMS)
uses
the
output
v
oltage
and
a
reference
to
set
the
output
to
the
MPPT
and
selects
an
appropriate
operating
mode
based
on
the
po
wer
deli
v
ered
and
demanded.
Unfortunately
,
the
y
only
considered
4
collectors
of
v
ery
lo
w
po
wer
.
The
authors
of
[31]
studied
a
solar
panel,
a
BB
and
tw
o
modes
of
operation
for
an
EMS.
F
or
the
first
mode
it
w
as
considered
that
the
panel
does
not
supply
enough
po
wer
and
the
BB
is
used
unti
l
the
maximum
current
point
in
the
inductor
is
reached.
In
the
second
mode,
it
w
as
considered
that
the
po
wer
of
the
panel
is
much
greater
than
that
desired
by
the
load
such
that
the
inductor
current
reaches
its
highest
point
and
be
gins
to
decrease,
this
allo
ws
the
BB
to
be
char
ged
with
the
remaining
current
in
inductor
.
The
authors
of
[32],
proposed
a
double
i
np
ut
and
double
output
con
v
erter
with
Pulse
W
idth
Modulation
(PWM)
controls
and
a
single
inductor
.
The
MPPT
w
as
used
as
a
determining
v
ariabl
e
of
the
modes
of
operati
on
;
while
the
po
wer
of
the
panel
is
greater
than
the
po
wer
of
the
load,
the
ener
gy
of
the
panel
is
transferred
to
the
load
and
in
turn
to
the
BB.
When
the
po
wer
of
the
panel
is
less
than
the
po
wer
of
the
load,
the
strate
gy
use
a
supplementary
state
in
which
the
BB
will
feed
the
load.
In
[33]
a
strate
gy
of
ener
gy
rec
ycling
w
as
proposed
considering
a
solar
panel
and
a
BB
that
feed
a
load
by
a
double
input
double
output
con
v
erter
with
single
inductor
.
The
strate
gy
used
the
MPPT
and
a
higher
v
oltage
selector
to
generate
the
PWM
pulses.
The
authors
in
[34]
and
[35]
presented
similar
topologies
and
control
strate
gies
based
on
the
detection
of
zero
crossing
in
v
oltage
or
current
to
inte
grate
tw
o
ener
gy
collectors
to
a
DC
load;
e
xperimental
e
vidence
w
as
presented
sho
wing
the
ef
fecti
v
eness
of
the
strate
gy
.
A
non-isolated
multi-input
single
output
con
v
erter
with
three
MOSFET
switche
s
per
stage,
that
can
operate
in
Buck
or
Boost
mode
independently
,
w
as
presented
in
[36].
The
authors
presented
a
mathematical
model,
b
ut
the
y
do
not
seem
to
consider
stability
,
equalization
or
decoupling
ef
fects
and
do
not
proposed
an
EMS.
In
[37]
the
authors
pro
vided
a
control
strate
gy
for
the
inte
gration
of
tw
o
solar
panels
with
the
po
wer
grid
and
po
wer
a
load.
In
such
research,
the
high
po
wer
f
actor
is
essential
for
the
de
v
elopment
of
an
MPPT
strate
gy
and
the
switches
were
acti
v
ated
at
zero-v
oltage
and
zero-current
thus
reducing
the
po
wer
losses.
The
article
presented
in
[38]
proposed
a
peculiar
configuration
for
se
v
eral
po
wer
supplies
such
as
a
solar
panel,
a
HC
and
a
BB.
In
order
to
re
gulate
the
output
v
oltage,
the
authors
proposed
a
non-isolated
con
v
erter
topology
with
a
minimum
number
of
components,
and
an
EMS
that
stands
out
for
its
easy
implementation.
In
[39]
the
authors
presented
a
configuration
of
n
boost
s
tages
in
parallel,
decoupled
by
the
primary
inductor
of
a
transformer
to
perform
the
MPPT
.
A
mathematical
model
and
its
analysis
in
a
stable
state
were
presented
to
establish
a
control
strate
gy
that
allo
ws
simultaneous
operation;
unfortunately
,
the
use
of
a
transformer
implies
additional
losses
and
the
strate
gy
does
not
guarantee
that
a
BB,
an
HC,
neither
a
SC
operates
simultaneously
.
It
should
be
noted
that
in
none
of
the
papers
re
vie
wed,
the
inte
gration
of
an
unlimited
number
of
ener
gy
collectors
is
performed
for
simultaneous
operation
with
an
EMS
that
manages
to
reduce
the
additional
de
gradation
to
which
the
po
wer
sources
can
be
subjected,
including
an
h
ydrogen
or
fuel
cell.
That
is,
it
is
recommended
that
the
BB
does
not
absorb
the
current
transients
([40–42]),
that
the
solar
panel
and
other
collectors
operate
in
the
MPPT
([43])
and
that
the
fuel
cell
pro
vides
a
quasi-constant
current
at
its
nominal
capacity
([44]).
In
addition,
the
de
v
elopment
of
such
a
system
is
a
rele
v
ant
problem
under
study
by
v
arious
research
groups
because
the
combined
use
of
v
arious
ener
gy
sources
in
an
EV
has
a
direct
benefit
not
only
in
its
scope,
b
ut
in
the
use
of
green
ener
gy
sources.
Ev
en
more,
from
the
state-of-art
re
vision
abo
v
e,
there
are
still
man
y
problems
related
to
the
i
nte
gration
of
ener
gy
harv
esting
de
vices
in
an
electric
or
h
ybrid
electric
v
ehicle.
In
this
article,
an
alternati
v
e
solution
to
the
problem
of
selecting
a
platform
that
allo
ws
the
use
of
a
sola
r
cell
and
a
battery
bank,
together
with
multiple
harv
esting
de
vices
in
an
electric
v
ehicle
is
presented
(po
wer
electronic
platform
and
the
EMS
algorithm
sk
etch).
This
alternati
v
e
considers
minimizing
de
gradation
of
the
fuel
cell
and
the
battery
bank
due
to
peaks
in
the
demanded
po
wer
,
which
according
to
the
manuf
acturer
,
cause
its
premature
de
gradation.
Also,
the
maximum
po
wer
generation
from
the
harv
esting
de
vices
is
ensured.
This
article
presents
the
follo
wing
contrib
utions
to
the
state
of
the
art:
(a)
A
ne
w
mathematical
model
is
obtained
for
a
n
stages,
bidirectional
Boost-Buck
con
v
erter
operating
in
CCM,
that
allo
ws
the
operation
of
SCs,
BBs,
re
generati
v
e
braking
motors
and
multiple
ener
gy
harv
est/storage
de
vices
simultaneously
in
an
EV
.
(b)
The
ef
fects
of
equalization
and
decoupling
of
the
stages
of
the
proposed
con
v
erter
are
analyzed.
This
allo
ws
to
inte
grate
sources
of
an
y
po
wer
le
v
els.
Harvesting
in
electric
vehicles:
Combining
...
(J
uan-Ger
ar
do
P
ar
ada-Salado)
Evaluation Warning : The document was created with Spire.PDF for Python.
5060
r
ISSN:
2088-8708
(c)
An
e
xperimental
v
alidation
of
the
model.
(d)
A
stability
analysis
is
performed
and
includes
the
dynamics
of
a
bounded
output
controller
.
(e)
A
MPPT
,
EMS
for
an
EV
with
the
proposed
con
v
erter
,
based
on
design
principles
that
include
the
pre
v
ention
of
premature
de
gradation
of
the
BB
and
HC,
is
designed.
The
EMS
is
modular
,
lo
w
cost
of
implementation
and
can
be
scaled
to
include
other
harv
esting
de
vices.
(f)
Semi-e
xperimental
tests
(real-time
simulations
with
hardw
are
in
v
olv
ed
or
Hardw
are-In-the-Loop
HIL)
are
presented
for
the
v
alidation
of
the
mathematical
model
and
the
ener
gy
management
strate
gy
,
from
which
can
be
inferred
the
implementation
of
the
EMS
at
lo
w
monetary
cost.
This
article
is
or
g
anized
as
f
o
l
lo
ws.
The
system
configuration,
description
a
n
d
its
analysis
are
presented
in
Section
2.
Numerical,
HIL,
and
e
xperimental
results
are
presented
in
Section
3.
In
Section
4
is
presented
a
brief
discussion
and
some
conclusions.
2.
SYSTEM
CONFIGURA
TION
AND
DESCRIPTION
A
general
scheme
of
the
proposed
con
v
erter
configuration
for
the
po
wer
stage
of
the
harv
esting
EV
is
sho
wn
in
Figure
1.
This
configuration
can
be
used
for
dif
ferent
scenarios,
therefore,
a
general
analysis
of
this
circuit
is
presented
first
and
then
particularized
to
the
EMS.
In
the
left
part
of
the
circuit
of
Figure
1,
there
are
se
v
eral
collectors/ener
gy
sources,
connected
in
parallel
to
the
CD
Bus
by
means
of
a
v
oltage
amplification
stage,
better
kno
wn
as
Boost
con
v
erters.
The
collectors/sources
include
a
solar
panel,
a
HC,
an
ener
gy-generating
damper
(EGD)
and
other
sources
(e.
g.
by
vibration,
heat,
etc.)
The
last
tw
o
are
considered
DC
signals
(rectified).
In
this
w
ay
,
the
number
of
collectors
is
not
limited,
and,
by
ha
ving
a
modular
design,
collectors
with
their
respecti
v
e
stages
can
be
remo
v
ed
or
added.
On
the
other
hand,
at
the
bottom
of
the
schematic,
there
are
the
ener
gy
storage
de
vices
(BB
and
SC)
and
finally
the
motor
of
the
EV
.
These
last
three
de
vices
are
connected
to
the
DC
b
us
through
tw
o-w
ay
(bidirectional)
con
v
erters
that
function
as
a
v
oltage
reducer
or
Buck
type
from
the
DC
b
us
to
the
de
vice
and
as
a
Boost
from
the
de
vice
to
the
DC
b
us.
In
this
w
ay
,
the
BB
and
SC
can
be
operated
independently
,
and
re
generati
v
e
braking
is
allo
wed.
Figure
1.
Schematic
of
the
general
n
stages,
parallel
con
v
erter
for
the
platform.
The
circuit
consist
of
paralleled,
bidirectional
stages
type
Boost
to
load
and
Buck
back
if
required
Int
J
Elec
&
Comp
Eng,
V
ol.
10,
No.
5,
October
2020
:
5058
–
5073
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5061
2.1.
Mathematical
model
of
the
con
v
erter
The
circuit
of
Figure
1
can
be
analyzed
with
a
resisti
v
e
load
that
demands
po
wer
from
the
DC
b
us
po
wered
by
n
de
vices.
The
motor
,
BB
and
SC
can
also
pro
vide
ener
gy
and
therefore
increase
the
maximum
n
-th
subscript.
An
a
v
eraged
model
obtained
in
continuous
conduction
mode
(CCM)
is:
L
1
_
I
1
=
u
1
V
bus
+
e
1
L
2
_
I
2
=
u
2
V
bus
+
e
2
.
.
.
L
n
_
I
n
=
u
n
V
bus
+
e
n
C
bus
_
V
bus
=
u
1
I
1
+
u
2
I
2
+
:::
+
u
n
I
n
V
bus
R
bus
L
m
1
_
I
m
1
=
e
m
1
+
u
m
1
V
bus
C
m
1
_
e
m
1
=
I
1
+
I
2
+
:::
+
I
n
I
m
I
m
2
e
m
1
R
m
1
L
m
_
I
m
=
e
m
+
u
m
V
bus
C
m
_
e
m
=
I
1
+
I
2
+
:::
+
I
n
I
m
1
I
m
2
e
m
R
m
(1)
where
R
bus
is
the
equi
v
alent
resistance
to
the
load
connected
on
the
b
us
and
R
m
2
,
R
m
1
and
R
m
the
equi
v
alent
resistances
of
the
stages.
From
the
equations
in
(1),
it
should
be
noted
that
duty
c
ycles
in
stationary
dynamics,
depend
in
v
ersely
on
V
bus
:
u
1
=
e
1
V
bus
.
.
.
u
n
=
e
n
V
bus
(2)
where
1
b
u
i
=
u
i
i
=
1
;
:::;
n
.
If
the
w
ork/duty
c
ycle
of
stage
0
b
u
i
u
max
0
:
8
is
less
than
the
equations
(2),
the
current
flo
w
through
the
diode
D
i
is
ne
gligible
due
to
the
lo
wer
potential
at
the
anode,
lea
ving
the
stage
isolated
(it
will
not
pro
vide
current
to
the
load)
re
g
ardless
of
the
v
alues
of
the
components
(
u
i
is
used
as
the
inacti
v
e
c
ycle.)
Similarly
,
if
the
current
of
the
source
e
i
is
not
enough
to
match
the
v
oltage
V
bus
the
stage
will
be
isolated
by
the
diode.
This
intrinsic
equalization
is
beneficial
in
the
case
of
an
EV
,
since
the
BB
re
gularly
has
the
greatest
capacity
to
pro
vide
current
while
protecting
the
inte
grity
of
the
other
de
vices
by
not
requiring
a
current
greater
than
the
y
can
pro
vide.
2.2.
Con
v
erter
closed
loop
stability
under
arbitrary
switching
The
time
deri
v
ati
v
e
of
the
b
us
v
oltage
in
(1)
with
0
<
u
min
u
i
1
,
for
i
=
1
;
:::;
n
,
where
u
min
is
the
minimum
v
alue
of
the
ina
cti
v
e
c
ycle
(approximately
0
:
2
and
limited
by
ph
ysical
characteristics
of
the
components)
is:
C
bus
•
V
bus
=
a
_
V
bus
bV
bus
+
c
(3)
where
a
=
1
R
bus
>
0
b
=
u
2
1
L
1
+
:::
+
u
2
n
L
n
>
0
c
=
u
1
e
1
L
1
+
:::
+
u
n
e
n
L
n
>
0
Re
writing
on
state
space
representation
and
shifting
to
the
operating
point
(recall
that
u
i
>
0
,
hence
b
>
0
)
x
1
=
V
bus
c
b
,
x
2
=
_
V
bus
one
has
:
_
x
=
Ax
(4)
Harvesting
in
electric
vehicles:
Combining
...
(J
uan-Ger
ar
do
P
ar
ada-Salado)
Evaluation Warning : The document was created with Spire.PDF for Python.
5062
r
ISSN:
2088-8708
where
A
=
0
1
b
a
:
Consider
controllers
0
<
u
i
(
t
)
=
k
i
V
bus
1
to
re
gulate
the
b
us
v
oltage
to
a
reference
V
r
ef
;
the
state
equations
are:
_
x
1
=
x
2
_
x
2
=
x
3
1
ax
2
(5)
where
=
k
2
1
L
1
+
:::
+
k
2
n
L
n
>
0
and
k
i
>
0
8
i
=
1
:::n
are
the
controller
g
ains.
T
o
demonstrate
stability
in
the
sense
of
[45],
consider
a
L
yapuno
v
candidate
function
V
=
1
4
x
4
1
+
d
1
2
x
2
2
with
d
>
0
;
V
(0)
=
0
,
V
(
x
)
>
0
8
x
6
=
0
and
its
deri
v
ati
v
e
along
the
system
paths
(5)
is
represented
by:
_
V
=
x
3
1
x
2
(1
d
)
dax
2
2
(6)
Selecting
d
=
1
=
one
has
_
V
=
a
x
2
2
<
0
;
8
x
2
6
=
0
(7)
and
then
the
stability
of
the
closed
loop
system
is
demonstrated.
Ev
en
more,
(
t
)
>
0
for
all
k
i
(
t
)
>
0
and
it
is
easy
to
sho
w
that
an
MPPT
control
is
a
u
i
(
t
)
=
k
i
(
t
)
V
bus
controller
(
k
i
(
t
)
=
f
i
(
I
i
(
t
))
);
hence,
the
stability
with
multiple
MPPT
controllers
for
feasible
v
alues
of
u
i
(
t
)
in
the
proposed
platform
is
demonstrated.
2.3.
Multiple
MPPT
ener
gy
management
strategy
In
the
scenario
proposed
in
the
pre
vious
sect
ion,
it
is
no
w
necessary
to
establish
an
EMS
that
complies
with
se
v
eral
design
principles;
EMS
must:
(a)
Maintain
the
BB’
s
SoC
from
the
a
v
ailable
ener
gy
sources.
(b)
Be
computable
in
real
time.
(c)
T
ak
e
adv
antage
of
all
the
ener
gy
a
v
ailabl
e
from
the
harv
esting
de
vices
(MPPT)
that
do
not
use
consumables
(i.e.
the
solar
panel,
EGDs,
etc.)
and
ultimately
that
obtained
from
the
HC.
(d)
Allo
w
the
HC
to
pro
vide
current
to
a
quasi-constant
and
limited
re
gime
due
to
its
intrinsic
operation.
(e)
Achie
v
e
that
the
SC
absorbs
rapid
ener
gy
demand
transients
to
pre
v
ent
premature
BB
and
HC
damage.
(f)
Allo
w
re
generati
v
e
braking.
W
ith
re
g
ard
to
criterion
5,
it
should
be
mentioned
that
lar
ge
current
transients
ha
v
e
been
sho
wn
to
cause
early
de
gradation
in
BBs
and
HCs,
re
g
ardless
of
their
chemistry
(see
for
instance
[40]).
Since
the
motor
can
pro
vide
ener
gy
when
performing
re
generati
v
e
braking,
the
EMS
is
di
vided
into
acceleration
and
re
generati
v
e
braking
modes
as
discussed
belo
w
.
2.3.1.
EMS
in
acceleration
mode
The
block
diagrams
o
f
the
proposed
EMS
are
depicted
in
Figure
2.
A
configuration
that
allo
ws
compliance
with
the
design
principles
mentioned,
and
in
acceleration
mode
is
sho
wn
in
Figure
2
(a).
Although
the
diagram
of
the
basic
con
v
erter
as
depicted
in
Figure
1
sho
ws
the
BB
connected
to
the
DC
b
us
through
a
tw
o-w
ay
Buck-Boost
stage,
for
the
proposed
EMS
such
a
stage
is
not
necessary
and
connects
directly
to
the
DC
b
us
of
the
load
that
includes
the
SC
and
R
L
with
its
Buck
and
Boost
stages
respecti
v
ely;
in
this
w
ay
,
the
SC
will
soften
the
demand
for
ener
gy
to
w
ards
the
BB
and
HC.
In
addition,
the
connection
of
an
SC
to
the
b
us
allo
ws
the
dec
o
upl
ing
of
the
stages,
making
the
equalization
sho
wn
in
equati
ons
(2)
unnecessary;
that
is,
in
this
w
ay
the
duty
c
ycles
will
not
depend
on
the
v
oltage
on
the
b
us
to
achie
v
e
a
current
control
per
stage.
F
or
the
present
w
ork,
the
BB,
the
SC
and
R
L
constitute
the
v
ariable
load
R
bus
that
depends
on
the
dri
ving
conditions
(of
the
v
ehicle)
as
sho
wn
in
Figure
2
(a).
Int
J
Elec
&
Comp
Eng,
V
ol.
10,
No.
5,
October
2020
:
5058
–
5073
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5063
(a)
(b)
Figure
2.
Block
diagram
of
the
proposed
EMS
(a)
in
acceleration
mode
and
(b)
in
re
generati
v
e
braking
mode.
The
motor
is
switched
to
po
wer
sources
side,
by
an
interrupter
in
the
brak
e
pedal
(relay).
This
block
diagram
is
possible
for
the
general
con
v
erter
of
Figure
1
by
making
L
m
2
=
0
and
M
b
2
=
1
,
and
inte
grating
a
v
ariable
speed
re
gulator
(Buck
con
v
erter)
at
motor
(slo
wly
v
ariable
load)
Since
the
BB
is
connected
to
the
DC
b
us,
_
V
bus
0
can
be
considered
(stationary
state);
that
is
to
say
,
it
is
of
much
slo
wer
dynamics
and
therefore
from
(1)
one
has:
V
bus
=
R
(
u
1
I
1
+
u
2
I
2
+
:::
+
u
n
I
n
)
(8)
pro
vided
that
u
i
e
i
V
bus
.
In
other
w
ords,
the
direct
connection
of
the
BB
to
the
CD
b
us
allo
ws
decoupling
the
n
stages
to
achie
v
e
the
injection
of
current
independently
.
On
the
other
hand,
the
load
that
is
no
w
modeled
as
a
resistor
(motor
winding)
and
is
connected
to
the
SC
through
a
Buck
con
v
erter
while
the
BB
is
connected
to
the
SC
t
hrough
a
Boost
stage;
in
this
w
ay
it
is
ensured
that
the
v
oltage
in
the
SC
is
at
least
the
potentia
l
of
the
BB
in
steady
state
and
the
re
gulation
of
current
demanded
by
the
dri
v
er
of
the
EV
denoted
as
I
r
ef
is
allo
wed.
A
proportional-inte
gral
controller
(PI)
allo
ws
re
gulating
the
duty
c
ycle
of
the
Boost
con
v
erter
from
BB
t
o
SC
and
in
turn
functions
as
a
lo
w-pass
filter
of
the
current
demanded
to
the
BB,
thus
complying
with
the
criterion
(e).
The
SoC
is
re
gulated
by
a
PI
controller
with
output
P
I
1
that
will
seek
to
maintain
98
%
(criterion
(a));
it
is
not
set
to
100
%
to
ensure
that
it
is
not
o
v
erloaded
causing
premature
de
gradation
[28].
Cascade
controllers
with
proper
tuning
allo
w
the
MPPT
from
the
ener
gy
sources
(criteria
(c)
and
(d))
and
delay
the
use
of
the
HC,
in
order
to
properly
establish
the
duty
c
ycles
of
each
of
the
Boost
stages
on
the
left
side
of
the
DC
b
us.
Proper
tuning
(slo
w
action)
allo
ws
a
quasi-constant
current
re
gime
to
be
e
xtracted
from
the
HC
(criterion
(d)).
The
current
references
I
a;M
P
P
T
,
I
p;M
P
P
T
(and
the
others
that
are
necessary
when
e
xtending
the
configuration)
can
be
obtained
through
commercial
circuitry
or
dedicated
softw
are
and
I
h;nom
is
obtained
from
the
manuf
acturer
.
I
a
,
I
p
and
I
h
represent
the
RMS
v
alue
of
current
supplied
by
the
auxiliary
(other),
solar
panel
and
HC
respecti
v
ely
.
Under
this
configuration,
other
ener
gy
harv
esting
and
ener
gy
storage
de
vices
can
be
easily
attached.
2.3.2.
EMS
in
r
egenerati
v
e
braking
mode
T
o
comply
with
the
criterion
(f),
the
con
v
erter
can
be
easily
reconfigured
using
a
contactor/relay
as
sho
wn
in
Figure
2
(b).
This
setting
is
acti
v
ated
by
a
switch
on
the
brak
e
pedal
that
puts
the
bi-directional
con
v
erter
of
the
motor
stage
in
Boost
mode
where
I
r
;M
P
P
T
represents
the
MPPT
current
reference.
Harvesting
in
electric
vehicles:
Combining
...
(J
uan-Ger
ar
do
P
ar
ada-Salado)
Evaluation Warning : The document was created with Spire.PDF for Python.
5064
r
ISSN:
2088-8708
Until
no
w
,
the
strate
gy
has
been
sho
wn
that
can
comply
with
all
design
principles
e
xcept
for
the
(b)
that
is
implementation-related.
The
implementation
for
real-time
operation,
being
simple
controllers
for
both
modes
of
operation
of
the
proposed
EMS,
does
not
represent
a
technical
dif
ficulty
using
e
v
en
lo
w-cos
t
digital
signal
processing
(DSP)
micro
controller
de
vices.
In
the
follo
wing
section,
it
is
demonstrated
that
it
is
possible
to
implement
both
the
controller
and
the
model
of
each
of
the
de
vices
in
v
olv
ed
in
real
time
with
inte
gration
time
of
6
s
.
2.4.
SoC
contr
ol
stability
In
order
to
v
erify
the
stability
under
the
action
of
the
proposed
controller
for
SoC
(which
dif
fers
from
the
MPPT
control
stability
presented
before
because
of
the
inte
gral
action),
the
state
of
char
ge
of
the
BB
can
be
estimated
as:
S
oC
=
S
oC
(0)
+
100
Q
Z
I
i
dt
(9)
where
Q
is
the
nominal
capacity
of
the
BB.
From
(1)
and
(8),
u
i
represents
the
inacti
v
e
c
ycle,
so
a
PI
controller
with
reference
r
can
be
defined
as:
u
i
=
1
k
i;p
(
r
S
oC
)
k
i;int
Z
(
r
S
oC
)
dt
(10)
Then
the
dif
ferential
equations
for
the
parallel
stages
(of
the
con
v
erter),
as
a
function
of
(8),
(9)
and
(10)
are:
•
S
oC
=
V
bus
k
i;p
_
S
oC
V
bus
k
i;int
S
oC
+
V
bus
k
i;int
r
0
:
01
L
i
Q
(11)
Clearing
SoC(s)
of
the
Laplace
transform
from
the
pre
vious
equation:
S
oC
(
s
)
=
V
bus
k
i;int
r
=s
L
i
Q
100
s
2
+
V
bus
k
i;p
s
+
V
bus
k
i;int
(12)
Using
the
Routh
Hurwitz
criterion
it
is
easy
to
demonstrate
that
the
system
is
stable
for
some
positi
v
e
g
ain
v
alues.
2.5.
Dimensioning
and
Output
Ripple
From
v
oltage
balances
in
steady-state
and
CCM
operation
for
each
stage
(as
re
gularly
used
for
si
ngle
Boost
stages),
one
can
obtain:
L
i
>
1
:
2
D
M
R
L
(1
D
M
)
2
2
f
(13)
where
D
M
is
the
maximum
duty
c
ycle
and
f
is
the
PWM
frequenc
y;
a
20%
increment
is
selected
for
ensure
CCM.
The
v
oltage
ripple
in
the
BB
can
be
conserv
ati
v
ely
determined
as:
V
B
B
=
V
B
B
D
M
R
B
B
C
B
B
f
(14)
where
V
B
B
is
the
nominal
v
oltage
of
the
BB
and
R
B
B
and
C
B
B
are
the
equi
v
alent
resistance
and
capacitance
in
the
BB.
3.
NUMERICAL
SIMULA
TIONS
AND
EXPERIMENT
AL
RESUL
TS
In
this
section,
are
presented
HIL,
and
e
xperimental
v
alidations
of
the
mathematical
model.
Subsequently
,
HIL
simul
ations
are
included
that
demonstrate
the
ef
fecti
v
eness
and
ease
of
implementation
of
the
EMS.
Int
J
Elec
&
Comp
Eng,
V
ol.
10,
No.
5,
October
2020
:
5058
–
5073
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5065
3.1.
HIL
V
alidation
of
the
mathematical
model
T
o
v
alidate
the
mathematical
model
obtained,
se
v
eral
simulations
were
performed
in
Simulink
and
the
dynamic
response
is
compared
with
the
circuit
emulated
in
HIL;
this
is,
T
yphoon
HIL402
platform
include
realistic
models
of
solar
panels,
batteries,
electronic
de
vices
as
MOSFETs,
among
others,
that
allo
ws
v
alidating
the
analytic
model
(numerically
solv
ed
in
Matlab).
This
Python-based,
compact
4-core
HIL
gi
v
es
all
the
tools
to
test
po
wer
electronics
controllers
in
a
wide
range
of
appl
ications
as
solar
and
wind
po
wer
generation,
battery
storage,
po
wer
quality
and
motor
dri
v
es;
also,
this
de
vice
allo
ws
to
test
controllers
in
real
ti
me
with
20
ns
PWM
resolution,
in
closed
loop
with
high-fidelity
po
wer
stage
with
1
M
H
z
update
rate.
Here,
only
representati
v
e
results
are
pro
vided.
The
T
yphoon
HIL402
platform
is
used
to
emulate
the
con
v
erter
stages
in
real
time
with
an
inte
grati
on
time
of
6
s
.
Sources
of
48
;
24
and
12
V
are
used
with
capacities
of
8
,
8
and
6
Ah
respecti
v
ely
,
2
:
2
,
2
:
0
,
and
2
:
5
mH
for
L
1
L
3
,
C
=
200
F
and
R
=
10
with
V
bus
=
60
V
,
u
1
=
0
:
20
,
u
1
=
0
:
60
and
u
1
=
0
:
80
.
Figure
3
sho
ws
the
comparisons
of
the
output
v
oltage
V
bus
and
the
currents
in
the
inductors
I
1
I
3
obtained
from
the
HIL
emulation
ag
ainst
the
dynamic
responses
of
the
mathematical
model
.
Although
there
is
a
transitional
stage
with
a
longer
duration
in
the
mathematical
model,
the
final
v
oltage
v
alue
is
60
V
on
a
v
erage.
It
should
be
noted
that
the
transient
is
of
longer
durati
o
n
because
in
the
HIL
emulation
the
v
oltage
sources
are
modeled
BBs
with
limited
current
capacity
,
while
in
the
mathematical
model
the
current
pro
vided
by
the
sources
is
unlimited.
In
the
lo
wer
trends
it
can
be
seen
that
the
a
v
erage
of
the
currents
in
the
inductors
in
the
HIL
emulation
is
v
ery
close
to
the
v
alue
of
the
currents
obtained
by
the
numerical
inte
gration
of
the
mathematical
model.
In
this
w
ay
it
could
be
concluded
that
the
mathematical
model
is
a
conserv
ati
v
e
representation
of
the
transitory
while
stationary
error
when
comparing
the
response
with
an
HIL
platform
is
2
:
5%
on
a
v
erage.
Figure
3.
Comparison
of
the
dynamic
response
of
the
con
v
erter
,
obtained
from
the
a
v
eraged
mathematical
model
vs
HIL
emulation
(switched).
The
a
v
erage
dynamics
ha
v
e
minimal
error
in
steady
state.
The
transitional
stage
is
slightly
dif
ferent
because
the
po
wer
sources
in
the
model
are
ideal
whereas
in
the
HIL
tests
the
y
are
battery
models;
In
addition,
the
dynamics
of
the
diode
are
ne
glected
in
the
m
o
de
l
(the
current
s
in
the
inductors
cannot
be
ne
g
ati
v
e)
3.2.
Experimental
v
alidation
of
the
mathematical
model
In
order
to
v
alidate
the
model
and
the
mentioned
equalization
phenomenon,
an
e
xperimental
platf
o
r
m
as
depicted
in
Figure
4
is
b
uilt
for
the
general
con
v
erter
of
Figure
1.
A
DSPIC30F4011
is
used
to
generate
the
PWM
signals,
15
H
inductors
(5711-RC)
are
calculated
for
D
M
=
0
:
5
and
f
=
20
k
H
z
with
three
5
V
sources
and
a
50
F
capacitor
is
calculated
for
a
0
:
1
v
oltage
ripple.
In
Figure
5
is
sho
wn
a
comparati
v
e
of
the
numerical
ag
ainst
e
xperimental
beha
vior
in
the
output
v
oltage;
note
that
the
a
v
erage
error
is
only
about
5%
for
equalized
duty
c
ycles.
In
Figure
6
are
sho
wn
the
inductor
currents
for
the
same
test;
note
that
all
stages
operate
in
CCM.
Harvesting
in
electric
vehicles:
Combining
...
(J
uan-Ger
ar
do
P
ar
ada-Salado)
Evaluation Warning : The document was created with Spire.PDF for Python.
5066
r
ISSN:
2088-8708
Figure
4.
PCB
of
the
e
xperimental
setup.
PWM
and
control
can
be
implemented
in
a
DSPIC30F
,
which
results
in
a
economical
and
ef
fecti
v
e
proposal
(a)
(b)
Figure
5.
Output
v
oltage
comparison,
(a)
numerical
ag
ainst
(b)
e
xperimental
with
equalized
duty
c
ycles.
The
steady
state
error
is
minimal
for
the
a
v
erage
v
oltage,
about
2%
(a)
(b)
(c)
Figure
6.
Inductor
current
in
(a)
L
1
,
(b)
L
2
,
and
(c)
L
3
with
equalized
duty
c
ycles.
All
inductor
currents
describe
a
CCM
operation
since
(2)
are
met
Int
J
Elec
&
Comp
Eng,
V
ol.
10,
No.
5,
October
2020
:
5058
–
5073
Evaluation Warning : The document was created with Spire.PDF for Python.
Int
J
Elec
&
Comp
Eng
ISSN:
2088-8708
r
5067
Belo
w
,
comparisons
are
presented
under
the
same
conditions
as
the
pre
vious
one,
b
ut
with
the
non-
equalized
duty
c
ycles
(
0
:
4
,
0
:
5
and
0
:
6
respecti
v
ely).
The
Figure
7
sho
ws
the
comparison
of
the
output
v
oltage
and
in
Figure
8
the
currents
in
inductors
are
sho
wn.
Notice
ho
w
when
the
c
ycles
are
not
equalized,
only
one
inductor
remains
operating
in
CCM
while
the
others
operate
in
DCM
(the
stage
with
greater
duty
c
ycle
remains
in
CCM);
also,
the
output
v
oltage
v
alue
no
longer
matches
the
model.
(a)
(b)
Figure
7.
Output
v
oltage
comparison.
(a)
numerical
and
(b)
e
xperimental
with
no
equalized
duty
c
ycles.
The
steady
state
error
is
lar
ge,
about
15%
,
since
(2)
are
not
met
(a)
(b)
(c)
Figure
8.
Inductor
current
in
(a)
L
1
,
(b)
L
2
,
and
(c)
L
3
with
no
equalized
duty
c
ycles.
Only
the
equalized
stage(s)
(stage
1)
operates
in
CCM,
the
rest
operates
in
DCM
3.3.
V
alidation
of
the
EMS
T
o
perform
the
tests
of
the
proposed
EMS,
it
is
implemented
together
with
the
mathematical
model
of
each
source
de
vice,
on
the
T
yphoon
HIL
platform;
this
allo
ws
to
sho
w
that
the
EMS
is
real-time
computable,
and
at
the
same
time
that
it
sho
ws
the
correct
operation
of
the
EMS
with
real
istic
models
of
the
de
vices.
The
current
reference
is
pro
vided
by
an
e
xternal
v
oltage
source
to
the
T
yphoon
emulating
the
position
of
the
EV
throttle.
T
yphoon
HIL
includes
a
solar
panel
model
whose
characteristic
curv
e
with
nominal
v
oltage
of
29
:
73
Harvesting
in
electric
vehicles:
Combining
...
(J
uan-Ger
ar
do
P
ar
ada-Salado)
Evaluation Warning : The document was created with Spire.PDF for Python.