Internati
o
nal
Journal of P
o
wer Elect
roni
cs an
d
Drive
S
y
ste
m
(I
JPE
D
S)
Vol
.
1,
N
o
.
2
,
D
ecem
b
er 20
1
1
, pp
. 10
4~
11
2
I
S
SN
: 208
8-8
6
9
4
&
1
04
Received Oct
11
th
,
2011; Revi
sed N
o
v
16
th
, 2011; Acce
pted
Nov
20
th
, 201
1
Design and Development of Hybrid
Multilevel Inverter employing
Dual Reference Modulation Techni
que for Fuel Cell Applications
R. Seyez
h
ai
*, B
a
nup
ar
va
th
y
K
a
l
p
an
a, Je
nni
fer V
a
sa
nt
hi
Department o
f
EEE, SSN Colleg
e
of
Engin
eering
,
Rajiv
Gandhi
Salai, Kalavakk
am -603110,
Tamilnadu
,
India.
Ph: 044-27475065, Ex
t: 394, Fax: 044-2746977
2
e-mail: sey
e
zhair@ssn.edu.in
, banunatar
a
jan89@
gmail.com
Abstract
MultiLevel
Inverter (
M
LI
)
has been recognized
as an at
trac
ti
ve topo
logy
for h
i
gh vo
ltage DC-AC con
version.
Thi
s
paper focuses o
n
a new dual reference modul
ation techniqu
e fo
r a hybrid multilevel
in
verter employing Silico
n
carbide (
S
iC)
switches for fuel cell application
s
. The pr
oposed modulation tech
nique emplo
y
s two
reference wa
veforms and a single in
verted
sine wave as
the carrier wavefor
m
. This
techniqu
e is
compared w
ith
th
e
conventio
nal dual carrier
waveform in
ter
m
s of output
voltag
e
spectral quality and swit
ching losses. An experimen
tal fi
ve
-level hybrid in
verter test ri
g has been built using SiC swi
tches
to implement
the proposed algorithm. Gating sign
als are generate
d using PIC microcontroller. Th
e performance o
f
the in
verter
has been analyz
ed and
compared with
the result obtained
from th
eory and simulation. S
i
mulatio
n st
udy of Propo
rtional Integral
(
P
I)
controller for the
inverter
employing
the proposed
modulation strategy has
been
don
e
in M
A
TLAB/SIMULINK.
Keywords:
Multilev
e
l
inver
t
er
,
SiC, dual r
e
fer
e
n
ce m
odulation
,
s
w
itching
losses,
PI
1.
In
tro
ducti
o
n
Fun
c
tio
n
of mu
ltilev
e
l in
v
e
rter is to
syn
t
h
e
size a d
e
sired
o
u
t
p
u
t
v
o
ltag
e
fro
m
sev
e
ral lev
e
ls o
f
DC i
n
pu
t
vol
t
a
ge
s [1]
.
A
s
t
h
e num
ber o
f
l
e
vel
s
i
n
creas
es, t
h
e sy
nt
hes
i
zed out
put
wa
vef
o
rm
has
m
o
re st
eps,
whi
c
h
pr
od
uces a
staircase wa
ve
that approaches the desi
red
wave
form
. They are of speci
al intere
st in the distri
bute
d
energy sources
area beca
use s
e
veral batteries
, fuel cell, sola
r cell and wi
nd
turbi
n
e can
be
connected th
ro
ugh
m
u
lti
lev
e
l in
v
e
rter to
feed
a lo
ad
with
ou
t vo
ltag
e
balan
ce p
r
ob
lem
s
[2
]. Th
ere
are sev
e
ral to
po
log
i
es o
f
m
u
lt
ilev
e
l in
v
e
rter
[3
], bu
t th
e one
con
s
i
d
ere
d
i
n
t
h
i
s
pa
per i
s
t
h
e
hy
bri
d
cascad
ed m
u
l
t
i
l
e
vel
inve
rt
er em
pl
oy
i
ng Si
C
base
d
swi
t
c
hes. T
h
e
adva
nt
age
s
o
f
th
e propo
sed to
po
log
y
ov
er
th
e ex
isting
on
es are red
u
c
ed
n
u
m
b
er o
f
swi
t
c
hes,
l
e
ss
num
ber
of c
a
paci
t
o
rs
an
d
si
m
p
lified
structu
r
e and
also
allo
w
the
use
of a si
ngle
dc
source
.
For the ca
scaded m
u
ltilevel inve
rter
va
riety of m
odula
tion
strate
gies ha
ve been
re
port
ed, with
t
h
e m
o
s
t
popular
being
carrier-ba
s
ed a
n
d space
vect
or m
odulation [4
]. Se
veral m
u
lti carrier techniques
have
be
en
devel
ope
d
to
redu
ce th
e
d
i
sto
r
tion
i
n
m
u
ltilev
e
l in
v
e
rt
er,
b
a
sed
o
n
t
h
e
classical SPW
M
with
tri
a
n
g
u
l
ar carriers [5
]. Bu
t t
h
is
pape
r f
o
c
u
ses
on a
du
al
refe
rence m
o
d
u
l
a
t
i
on t
e
c
hni
que
wi
t
h
a si
n
g
l
e
i
nve
rt
ed si
ne w
a
ve car
ri
er wa
vef
o
rm
. The
adva
nt
age
s
of i
nve
rt
ed si
ne w
a
ve are en
hanc
ed fu
n
d
am
ent
a
l
vol
t
a
ge, re
du
ced Tot
a
l
Har
m
oni
c Di
st
ort
i
on (
T
H
D
) a
n
d
swi
t
c
hi
n
g
l
o
sse
s. T
h
e p
r
op
ose
d
m
odul
at
i
o
n i
s
com
p
ared
wi
t
h
dual
ca
rri
er
a
n
d
si
n
g
l
e
re
fer
e
nce m
odul
at
i
o
n t
ech
ni
q
u
e.
An i
n
vert
e
d
si
ne wa
ve of
hi
gh s
w
i
t
c
hi
n
g
f
r
eq
ue
ncy
i
s
t
a
ken as a carri
er wav
e
an
d i
s
com
p
ared wi
t
h
t
h
at
of t
h
e
refe
rence si
ne
wave
. The
pulses are ge
nerate
d whe
n
eve
r
the
a
m
pl
i
t
ude of t
h
e re
fere
nce si
ne wa
ve i
s
g
r
e
a
t
e
r t
h
an t
h
at
of t
h
e i
n
vert
e
d
si
ne carri
er w
a
ve. PIC
m
i
crocont
rol
l
e
r i
s
us
ed t
o
o
b
t
a
i
n
t
h
e gat
i
ng pat
t
e
r
n
fo
r t
h
e i
ndi
vi
dual
I
G
B
T
S.
A det
a
i
l
e
d st
u
d
y
o
f
t
h
e
pr
op
ose
d
m
odul
at
i
on t
e
c
hni
qu
e i
s
carri
e
d
o
u
t
t
h
ro
u
gh M
A
TL
AB
/
S
IM
U
L
I
N
K f
o
r s
w
i
t
c
hi
n
g
l
o
sses an
d TH
D. F
u
rt
h
e
rm
or
e, a PI co
nt
rol
l
er i
s
used t
o
c
ont
rol
t
h
e M
L
I
usi
n
g t
h
e pr
o
pos
ed P
W
M
t
echni
que
. The
resul
t
s
we
re ve
ri
fi
ed ex
pe
ri
m
e
nt
al
l
y
. It
was
not
i
ced t
h
at
t
h
e pro
p
o
se
d
m
odul
at
i
o
n st
rat
e
gy
resul
t
s
i
n
l
o
wer swi
t
c
hi
n
g
losses
for a
chose
n
T
H
D as c
o
m
p
ared t
o
the
conve
ntional s
t
rategies.
2
.
Hy
brid Casca
d
ed Multilev
e
l
Inv
erter
The
pr
o
pose
d
cascade
d
m
u
l
t
i
l
e
vel
i
nve
rt
er
as sh
o
w
n i
n
F
i
g.1
co
nsi
s
t
s
o
f
a
ful
l
-
bri
dge
i
nve
rt
er,
capa
c
i
t
o
r
v
o
ltag
e
d
i
v
i
d
e
r, an
aux
iliary circu
it co
m
p
risin
g
fou
r
SiC
dio
d
e
s an
d
a Si
IGBT switch
[6
]. Th
e inv
e
rter p
r
od
u
c
es
out
put
v
o
l
t
a
ge
i
n
fi
ve l
e
vel
s
:
z
e
ro
,
0.
5V
dc,
V
dc
, -
0
.
5
V
dc
and
-
V
dc
. The
adva
ntages
of the
inverter topol
ogy are:
•
Im
prove
d o
u
t
p
ut
v
o
l
t
a
ge q
u
al
i
t
y
•
Sm
a
ller filter size
•
Lower EMI
•
Lower
THD com
p
ared
with co
nv
en
tio
n
a
l
th
ree- lev
e
l
PW
M
•
Red
u
c
ed
nu
mb
er of switch
e
s co
m
p
ared to
t
h
e co
nv
en
tion
a
l 5
-
lev
e
l inv
e
rt
er
The ci
rc
ui
t
ope
rat
i
on i
s
ex
pl
ai
ned as f
o
l
l
o
ws:
The swi
t
c
hes
S
1
, S
2
and S
3
will b
e
switch
e
d
at th
e rate o
f
th
e
carrier
signal fre
que
ncy whi
l
e
S
4
and S
5
will o
p
e
rate at
a frequ
e
n
c
y
eq
u
a
l t
o
th
e fu
nd
am
en
tal freq
u
e
n
c
y.
Th
e
ope
rat
i
o
n i
s
di
vi
de
d i
n
t
o
fo
u
r
m
odes.
In
m
ode1
,
s
w
i
t
c
hes
S
1
and
S
5
co
ndu
ct an
d th
e
d
i
od
es
D
1
and
D
4
are
forward
bi
ased
. The o
u
t
put
v
o
l
t
a
ge eq
ual
s
t
o
+ 0.5
V
dc
. In m
ode 2, s
w
i
t
c
hes S
2
and S
5
cond
uct
.
T
h
e o
u
t
p
ut
vol
t
a
ge eq
ual
s
t
o
Evaluation Warning : The document was created with Spire.PDF for Python.
IJPE
DS
Des
i
+V
dc
. I
n
m
to
–0
.5V
d
conducti
o
3.
Pr
op
o
D
sine wa
v
e
The two
a
m
p
litu
d
e
V
ref
2
tak
e
N
t
echni
q
u
e
th
is m
o
d
u
i
gn
an
d
D
e
ve
l
m
ode 3,
s
w
i
t
c
d
c
. M
ode
4
d
e
o
n sequ
en
ce
o
o
sed Du
al
Re
f
D
ual refe
ren
c
e
carri
er for
g
re
fere
nce sig
n
e
of t
h
e carri
e
e
s
over the c
o
m
A
m
pl
i
t
ude
(
V
)
N
or
m
a
ll
y, (
m
e
em
pl
oy
s o
n
l
u
lation
techn
i
q
S
1
ON
OFF
OFF
ON
OFF
l
op
ment
of
Hy
c
hes S
1
and
S
4
e
sc
ribe
s the
c
o
f switch
e
s is
s
f
erenc
e
Mod
u
c
e
m
odul
at
i
o
n
g
ene
r
ating P
W
n
als will tak
e
e
r si
gn
al V
ref
2
m
pari
so
n pr
o
c
Fi
g. 1
C
A
m
pl
i
t
ude
(V)
Fig.
m
-
1
) ca
rrie
r
s
a
l
y a sing
le ca
r
q
ue i
s
gi
ve
n
b
S
2
OFF
ON
OFF
or
(ON
)
OFF
OFF
ISS
N
y
bri
d
M
u
ltile
v
c
o
nduct and
c
o
ndu
ctio
n
of
s
ho
wn
i
n
Tab
l
u
l
a
ti
on Tech
n
n
t
e
chni
que e
m
W
M
p
ulse
s fo
r
tu
rn
s t
o
b
e
c
2
will b
e
co
m
c
ess un
til it e
x
C
ircu
it Diagr
a
Tabl
e 1.
C
o
n
d
2
D
u
al
ref
e
r
e
a
re
nee
d
ed
t
o
r
rier si
gnal le
a
b
y:
S
O
O
)
O
o
(O
O
O
N
: 208
8-8
6
9
4
v
el Inverter
e
m
the diodes
D
2
sw
itc
h
e
s S
3
a
l
e 1 [7].
n
ique
m
pl
o
y
s
t
w
o r
e
r
th
e fu
ll brid
g
c
om
pared wi
t
h
m
pared wi
t
h
c
a
x
ceeds
the c
a
r
r
a
m
of Hy
bri
d
d
uct
i
o
n
se
qu
e
Ti
m
e
(
s
e
nce
an
d ca
rr
i
o
pr
od
uce ‘
m
a
di
ng
t
o
si
m
p
l
S
3
FF
FF
O
N
or
FF)
FF
O
N
m
pl
oyi
n
g Du
a
l
a
nd
D
3
ar
e
f
o
a
nd
S
4
wher
e
e
fere
n
ce sign
g
e inverter
an
h
a single car
r
a
rrier si
g
n
a
l
u
r
ier sign
al.
MLI (f
iv
e-
le
v
e
n
c
e of switc
h
s
)
er wa
veform
s
m
’ lev
e
l in
M
l
ified
pu
lse
g
e
S
4
OFF
OFF
ON
or
(OFF)
ON
ON
l
Ref
e
rence
M
o
rwa
r
d bi
ase
d
th
e
ou
tpu
t
v
als V
re
f1
and
d
aux
iliary ci
r
r
ier at a tim
e
.
u
ntil it reach
e
v
el inve
rter)
h
es
s
fo
r
M
L
I
M
LI [8]
.
But,
e
ne
rat
i
o
n. T
h
e
S
5
ON
ON
ON
or
(OFF)
OFF
OFF
M
o
dul
a
t
i
on …
.
. The
output
v
ol
t
a
ge
eq
ual
s
V
re
f
2
and a s
i
r
cuit as show
n
.
If
Vre
f
1
exc
e
s 0
.
At th
is
p
o
t
h
e pr
o
pos
e
d
e
m
odul
at
i
on
i
V
inv
+0.5V
dc
+V
dc
0
-0
.5
V
dc
-V
dc
&
(
R
. Sey
e
zh
ai
)
10
5
v
o
l
t
a
ge eq
ual
s
to
–V
dc
. T
h
e
i
ngl
e i
n
ve
r
t
e
d
n
i
n
F
i
g
u
r
e
2
.
e
eds the pea
k
o
in
t on
wards
,
d
m
o
du
latio
n
i
nde
x (m
a
) fo
r
)
5
s
e
d
.
k
,
n
r
Evaluation Warning : The document was created with Spire.PDF for Python.
&
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
1
,
No
.
2
,
D
ecem
b
er
2
011
:
10
4 – 112
10
6
c
m
a
A
A
m
2
=
(1
)
whe
r
e A
m
represents the
pea
k
val
u
e of the
refe
rence
wa
ve
form
and A
c
re
prese
n
ts the
pe
ak-peal val
u
e
of t
h
e carrier
wave
f
o
rm
. Th
e p
u
l
s
es
ge
ne
rat
e
d
usi
n
g
t
h
e p
r
o
p
o
se
d m
o
d
u
latio
n techn
i
qu
e is
u
s
ed to
tri
g
g
e
r the IGBTs i
n
a
seq
u
ent
i
a
l
m
a
nner
suc
h
t
h
at
t
h
e
desi
re
d
out
put
i
s
o
b
t
a
i
n
e
d
. T
h
e
gat
i
n
g
p
u
l
s
e
obt
ai
ne
d i
n
M
A
TLAB
/
S
I
M
U
L
I
N
K
i
s
sho
w
n i
n
Fi
g.
3.
Fi
g. 3 Gat
i
n
g p
a
t
t
e
rn
f
o
r
M
L
I
usi
n
g
t
h
e dual
refe
rence
m
odul
at
i
on
t
e
c
h
ni
q
u
e
0
0.
00
5
0.
01
0
.
015
0.
0
2
0.
025
0.
03
0.
035
0.
04
-1
-0
.
5
0
0.
5
1
1.
5
2
Ti
me
(
s
)
S1
P
W
M s
w
i
t
ch
i
n
g
p
a
tte
r
n
f
o
r
sw
i
t
ch
S
1
0
0.
00
5
0.
01
0
.
015
0.
0
2
0.
025
0.
03
0.
035
0.
04
-1
-0
.
5
0
0.
5
1
1.
5
2
Ti
me
(
s
)
S2
P
W
M s
w
i
t
ch
i
n
g
p
a
tte
r
n
f
o
r
sw
i
t
ch
S
2
0
0.
00
5
0.
01
0
.
015
0.
0
2
0.
025
0.
03
0.
035
0.
04
-1
-0
.
5
0
0.
5
1
1.
5
2
Ti
me
(
s
)
S3
P
W
M
sw
i
t
ch
i
n
g
si
g
n
a
l
f
o
r
sw
i
t
ch
S
3
0
0.
005
0.
01
0.
015
0.
02
0.
025
0.
03
0.
035
0.
04
-1
-0.
5
0
0.
5
1
1.
5
2
Ti
me
(
s
)
S
4
P
W
M sw
i
t
ch
i
n
g
si
g
n
a
l
f
o
r
sw
i
t
ch
S
4
0
0.
00
5
0.
01
0
.
015
0.
0
2
0.
025
0.
03
0.
035
0.
04
-1
-0
.
5
0
0.
5
1
1.
5
2
Ti
me
(
s
)
S
5
P
W
M
s
w
it
c
h
ing pa
t
t
e
rn f
o
rs
w
i
t
c
h S5
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
&
Design
and De
velopment
of
Hybrid Multilevel Inverter em
pl
oying
Dual Ref
e
rence M
o
dul
ation …. (R.
Sey
e
zhai)
10
7
The
pr
o
p
o
s
ed
m
odul
at
i
on t
e
c
hni
que
i
s
c
o
m
p
ared
wi
t
h
d
u
al
i
nve
rt
ed si
ne
w
a
ve ca
rri
er
wa
ve as
sh
o
w
n
i
n
Fi
g.
4
.
Ti
m
e
(s
)
A
m
p
lit
u
d
e (
V
)
Fig.4.
Dual carrier a
n
d a si
ngl
e refe
re
nce
wa
vef
o
rm
s fo
r M
L
I
4.
Perform
a
nce
Evaluation Of Hy
brid Mli
Employin
g
Du
al
Refere
n
ce
Moulation Technique
The pe
rf
o
r
m
a
nce eval
uat
i
o
n [
9
]
of d
u
al
re
f
e
rence m
odul
a
t
i
on t
ech
ni
q
u
e em
pl
oy
i
ng i
n
v
e
rt
ed si
ne
wav
e
as
carri
er f
o
r a singl
e
-
p
h
ase fi
v
e
-l
evel
i
nve
rt
er has bee
n
d
o
n
e
usi
ng M
A
TL
AB
and t
h
e
op
t
i
m
u
m
swi
t
c
hi
ng f
r
e
que
ncy
(f
s
=12
k
Hz)
with
m
i
n
i
m
i
zed
t
o
tal h
a
rm
o
n
i
c d
i
sto
r
tion
an
d
switch
i
ng
lo
ss
is d
e
term
in
ed
. Th
e sim
u
latio
n
resu
lt for th
e
l
o
ad v
o
l
t
a
ge i
s
sho
w
n i
n
Fi
g.
5. The va
ri
at
i
on
of T
HD wi
t
h
th
e ch
an
g
e
i
n
th
e switch
i
ng
frequ
en
cy is sh
own
in
th
e
Fig. 6.
T
h
e
T
H
D decrease
s
with
inc
r
ease i
n
s
w
itching
fre
quency.
Fi
g. 5 Si
m
u
l
a
t
e
d fi
ve-l
e
v
el
out
put
wa
vef
o
rm
of
hy
bri
d
M
L
I
S
w
i
t
c
h
i
n
g
F
r
e
que
n
c
y (
k
H
z
)
TH
D
(
%
)
Fi
g. 6 TH
D Vs
swi
t
c
hi
ng
f
r
eq
uency
Evaluation Warning : The document was created with Spire.PDF for Python.
&
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
1
,
No
.
2
,
D
ecem
b
er
2
011
:
10
4 – 112
10
8
Tabl
e 2 sh
o
w
s
t
h
e com
p
ari
s
on of T
H
D fo
r
bot
h d
u
al
carri
er an
d d
u
al
ref
e
rence m
odul
a
t
i
on t
echni
qu
e
s
for
m
a
=0.7
5 an
d f
s
=12
kHz
.
It
i
s
ob
vi
o
u
s t
h
at
t
h
e dual
refe
renc
e
m
odul
at
i
on t
echni
que
wi
t
h
i
nve
rt
ed si
ne
wave
has l
e
ss
THD
c
o
m
p
ared t
o
d
u
al
ca
rri
e
r
m
odul
at
i
o
n t
e
chni
que
.
Table
2 Com
p
aris
on
of Dual Re
ference
& Dual
Carrier Modul
ati
o
n Technique
4.
1. Sw
i
t
chi
n
g
L
o
sses
Switch
i
ng
lo
ss is th
e p
o
wer
dissip
a
tio
n
d
u
ri
n
g
t
u
rn
-on
a
nd tu
rn-o
ff switch
i
ng
trans
itio
ns. In
h
i
gh
frequ
e
n
c
y
P
W
M
,
s
w
i
t
c
hi
ng l
o
ss can
be
subst
a
nt
i
a
l
an
d m
u
st
be con
s
i
d
ere
d
i
n
t
h
e
t
h
erm
a
l
desi
gn
of t
h
e i
n
ve
rt
er. It
i
s
a bi
g
dra
w
back that results in a series of pr
oblem
s
such as increa
sing th
e cost of the inve
rter and
decreasi
ng i
t
s efficiency
in
h
i
gh
vo
ltage an
d
h
i
gh
pow
er
ap
p
lication
s
.
H
i
gh
er
th
e p
o
wer bei
n
g pr
ocesse
d,
t
h
e m
o
re
severe the effect of the
swi
t
c
hi
n
g
l
o
ss
bec
o
m
e
s. Sw
i
t
c
hi
ng l
o
ss a
n
al
y
s
i
s
fo
r
H
C
M
L
I i
s
a co
m
p
l
e
x proce
s
s
d
u
e t
o
t
h
e w
i
de n
u
m
b
er o
f
switching states of t
h
e inverte
r
[10].
T
h
e m
o
st accurate m
e
thod
of
determ
ining
switc
hing losses is to pl
ot the curre
nt
and
v
o
l
t
a
ge
wa
vef
o
rm
i
n
t
h
e
c
ont
rol
l
a
bl
e
swi
t
ch d
u
r
i
n
g t
h
e
swi
t
c
hi
n
g
t
r
ans
i
t
i
on an
d
m
u
l
t
i
pl
y
t
h
e
wa
vef
o
rm
poi
nt
by
poi
nt
t
o
get
a
n
i
n
st
ant
a
ne
o
u
s
po
we
r wa
ve
fo
r
m
. The area
un
der
t
h
e
p
o
we
r
cur
v
e i
s
t
h
e s
w
i
t
c
hi
ng e
n
e
r
gy
at
t
u
r
n
-
o
n
o
r
t
u
r
n
-
o
f
f
. T
h
e
equat
i
ons
g
o
v
er
ni
n
g
t
h
e
c
a
l
c
ul
at
i
on
of
swi
t
c
hi
n
g
l
o
ss
fo
r
bri
d
ge
H
1
con
s
istin
g o
f
Si IGBT
(FG
A
2
5
N
12
0
)
and Si
di
ode (
f
ast
reco
ve
ry
d
i
ode FR
10
7) a
r
e gi
ven
bel
o
w
and t
h
e s
w
i
t
c
hi
ng e
n
er
gy
i
s
o
b
t
a
i
n
ed
fro
m
the area
under
the power curve. T
h
e e
quations
go
ve
rni
n
g
t
h
e s
w
i
t
c
hi
n
g
l
o
ss i
s
gi
ve
n
by
s
ws
w
s
w
Pf
E
=
(2
)
whe
r
e, P
sw
is th
e switch
i
n
g
l
o
ss of IGBT, f
sw
is th
e switc
h
i
ng
frequ
en
cy, E
sw
i
s
t
h
e swi
t
c
hi
ng e
n
er
gy
.
T
he swi
t
c
hi
n
g
ener
gy
i
s
gi
ve
n
by
s
wo
n
o
f
f
EE
E
=+
(3
)
whe
r
e,
E
on
re
presents turn-on
energy los
s
, E
of
f
r
e
pr
esen
ts turn
of
f en
erg
y
lo
ss.
Th
e ex
pr
essio
n
fo
r E
on
a
nd
E
off
i
s
gi
ve
n
by
0
1
()
.
2
to
n
on
CE
C
o
n
EP
t
d
t
V
I
t
==
∫
(4
)
0
1
()
2
ff
to
f
f
oC
E
C
o
f
f
EP
t
d
t
V
I
t
==
∫
(5
)
There
f
ore,
t
h
e
swi
t
c
hi
n
g
e
n
er
gy
i
s
gi
ve
n by
()
1
2
s
w
C
E
c
on
of
f
EV
I
t
t
=+
(6)
The
di
o
d
e s
w
i
t
c
hi
n
g
l
o
ss i
s
gi
ven
by
s
rr
RM
o
swD
f
t
I
V
P
2
1
=
(7
)
whe
r
e, P
swD
re
prese
n
t
s
t
h
e di
ode s
w
i
t
c
hi
n
g
l
o
ss, V
o
represen
ts th
e vo
ltage, t
rr
represe
n
ts the reve
rse recove
ry tim
e
,
I
RM
repre
s
ents
the pea
k
re
ver
s
e reco
very
c
u
rre
nt, f
s
re
pre
s
ent
s
t
h
e swi
t
c
hi
n
g
f
r
eq
ue
ncy
.
The Si
C
di
od
e chose
n
f
o
r
au
x
iliary circuit fo
r h
ybrid
MLI h
a
s h
i
gh rev
e
rse
b
r
eakd
own
vo
ltag
e
, less rev
e
rse reco
v
e
ry cu
rrent, less rev
e
rse
recovery tim
e and the
sim
u
lated
resul
t
s
a
r
e s
h
o
w
n i
n
Ta
bl
e
3.
Type
of
Carr
ier
Dual Re
feren
c
e
(THD)
Dual
Carrier
(THD)
In
vert
e
d
si
ne
wave
6.
78
%
8.
55
%
Saw
To
ot
h
wa
ve
7.
66
%
9.
32
%
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
&
Design
and De
velopment
of
Hybrid Multilevel Inverter em
pl
oying
Dual Ref
e
rence M
o
dul
ation …. (R.
Sey
e
zhai)
10
9
Tabl
e 3
C
o
m
p
ari
s
o
n
of
I
rr
and
t
rr
for Si a
n
d
SiC diode
Par
a
meter
Si
Dio
d
e
SiC
Diode
Rev
e
rse reco
v
e
r
y
c
u
rren
t
(I
r
r
) 100A
20A
Reverse recover
y
t
i
m
e
(t
rr
) 60ns
20ns
The s
w
i
t
c
hi
n
g
l
o
sses f
o
r hy
b
r
i
d
M
L
I
usi
ng
dual
refe
re
nce m
odul
at
i
on
t
e
c
hni
que f
o
r vari
ous
swi
t
c
hi
ng fre
que
nci
e
s
are calculated
and gra
p
h is s
h
own i
n
Fi
g.
7.
Fi
g.
7 S
w
i
t
c
hi
n
g
l
o
ss
Vs S
w
i
t
c
hi
n
g
fre
que
nc
y
Pro
p
o
rtio
nal I
n
teg
r
al (P
I) c
ont
roller
[1
1,
1
2
]
is em
ploy
ed
to
regu
late th
e lo
ad vo
ltag
e
of
h
y
b
r
i
d
MLI and
the
cont
rol
l
e
r i
s
t
u
ned
usi
n
g Zei
g
l
e
r’
s Ni
col
s
m
e
t
hod. T
h
e s
i
m
u
l
a
t
i
on para
m
e
t
e
r for t
h
e
cl
osed l
o
o
p
co
nt
r
o
l
of
hy
bri
d
M
L
I i
s
s
h
ow
n i
n
Ta
bl
e
4.
Tabl
e
4.
Si
m
u
l
a
t
i
on Pa
ram
e
ters
fo
r C
l
ose
d
l
o
o
p
C
o
nt
rol
o
f
M
L
I
The cl
osed
l
o
o
p
l
o
a
d
v
o
l
t
a
ge
and
l
o
a
d
c
u
r
r
e
n
t
wa
ve
fo
rm
s of
hy
bri
d
M
L
I
i
s
sh
ow
n i
n
Fi
g
.
8
.
Ti
m
e
(
s
)
L
oa
d V
ol
t
a
g
e
(
V
)
L
oa
d C
u
rre
n
t
(A
)
Fig
.
8
Cl
o
s
ed lo
op
stead
y
-
s
tat
e
r
e
sp
on
se of
l
o
ad vo
ltag
e
and
lo
ad
cur
r
e
n
t
of
h
ybr
id
MLI
Par
a
meters
Values
I
nput Voltage (
V
i
n
) 100
volt
Ref
e
ren
ce Vo
ltag
e
(V
ou
t
) 80
volt
Fr
equency
of the car
r
i
er
(
f
c
) 1200
0
Hz
Pr
opor
tional const
a
nt (K
p
)
0.
6
I
n
tegr
al constant(K
i
)
1000
For Filter:
Inductance (L)
Capacitance (C)
400
m
H
2500
uF
Evaluation Warning : The document was created with Spire.PDF for Python.
&
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
1
,
No
.
2
,
D
ecem
b
er
2
011
:
10
4 – 112
11
0
5.
Experimental Resul
t
s
To ex
pe
ri
m
e
ntal
l
y
val
i
d
at
e t
h
e hy
bri
d
cascaded M
L
I usi
n
g
t
h
e pr
op
ose
d
m
odul
at
i
on, a
pr
ot
ot
y
p
e
fi
ve-
l
evel
in
v
e
rter h
a
s b
e
en
b
u
ilt
u
s
i
n
g
FGA25N120
Si
IGBT
fo
r
t
h
e fu
ll
b
r
idg
e
i
n
v
e
rter and
CSD100
060
SiC
d
i
od
e as t
h
e
swi
t
c
hi
n
g
de
vi
ces as s
h
ow
n i
n
Fi
g.
9.
The
ga
t
i
ng si
gnal
s
a
r
e
ge
nerat
e
d
usi
n
g P
I
C
1
8F
4
5
5
0
m
i
croco
n
t
r
ol
l
e
r.
a. Gat
i
n
g
pat
t
e
rn
f
o
r
t
h
e s
w
i
t
c
h S
1
(t
he
swi
t
c
hi
n
g
pat
t
e
rn
o
b
t
ai
ned
fr
om
po
rt
B
o
f
P
I
C
1
8F
45
5
0
)
b
.
Gatin
g p
a
ttern
for th
e switch
S
2
(t
he s
w
i
t
c
hi
n
g
pat
t
e
rn
o
b
t
ai
ned
fr
om
po
rt
B
o
f
P
I
C
1
8F
45
5
0
)
c. Gating
p
a
ttern fo
r th
e switch
S
3
(t
he s
w
i
t
c
hi
n
g
pat
t
e
rn
o
b
t
ai
ned
fr
om
po
rt
B
o
f
P
I
C
1
8F
45
5
0
)
d
.
Gating
p
a
ttern fo
r th
e switch
S
4
(t
he
s
w
i
t
c
hi
n
g
pat
t
e
rn
o
b
t
ai
ned
fr
om
po
rt
B
o
f
P
I
C
1
8F
45
5
0
)
e. Gating
p
a
ttern fo
r th
e switch
S
5
(t
he s
w
i
t
c
hi
n
g
pat
t
e
rn
o
b
t
ai
ned
fr
om
po
rt
B
o
f
P
I
C
1
8F
45
5
0
)
Fig
.
9
Gatin
g pattern
for th
e switch
e
s i
n
h
ybrid
MLI
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
&
Design
and De
velopment
of
Hybrid Multilevel Inverter em
pl
oying
Dual Ref
e
rence M
o
dul
ation …. (R.
Sey
e
zhai)
11
1
The
har
d
ware
i
m
pl
em
ent
a
t
i
on o
f
hy
bri
d
M
L
I
i
s
sh
o
w
n
i
n
Fi
g.
10
.
Fi
g.
10
P
hot
og
r
a
ph
f
o
r
ha
r
d
wa
re i
m
pl
em
ent
a
ti
on
o
f
Hy
bri
d
M
L
I
The e
x
peri
m
e
nt
al
l
o
ad
vol
t
a
g
e
o
f
fi
ve-l
e
v
el
i
nve
rt
er
f
o
r R
-
l
o
ad
(R
=
3
0
oh
m
s
) i
s
sho
w
n
i
n
Fi
g.
1
1
Fi
g .
1
1 Fi
ve-l
e
v
el
v
o
l
t
a
ge
o
f
hy
b
r
i
d
M
L
I
6.
C
o
ncl
u
si
on
Thi
s
pa
per ha
s
prese
n
t
e
d a h
y
b
ri
d M
L
I
wi
t
h
Si
C
di
ode
s fo
r fuel
cel
l
ap
pl
i
cat
i
ons.
A n
ovel
d
u
al
refe
r
e
nce
m
odul
at
i
on t
e
c
hni
que em
pl
oy
i
ng i
n
ve
rt
ed si
newa
ve ca
rri
er
has b
een i
nve
st
i
g
at
ed. T
h
e
p
e
rf
orm
a
nce pa
ram
e
t
e
rs of
t
h
e i
nvert
e
r
su
ch as THD a
n
d swi
t
c
hi
n
g
l
o
sses has bee
n
anal
y
zed. It
w
a
s fo
un
d t
h
at
dual
re
fere
nce
m
odul
at
i
o
n
t
echni
q
u
e
fo
r
hy
b
r
i
d
M
L
I
r
e
sul
t
e
d i
n
red
u
ced T
HD
of a
b
o
u
t
6
.
7
8
% at
a
m
odul
at
i
o
n i
nde
x
of
0.
75 a
nds
wi
t
c
hi
ng
fre
que
ncy
of
12
k
H
z c
o
m
p
ared t
o
t
h
e
c
o
n
v
ent
i
o
nal
si
n
g
l
e
refe
rence
a
nd
d
u
al carrier technique.
A suitable PI
cont
rol
l
e
r
has
been
desi
g
n
ed
t
o
re
gul
at
e t
h
e
out
put
v
o
l
t
a
ge
of M
L
I.
The
r
e
sul
t
s
o
f
si
m
u
l
a
t
i
on
have
bee
n
veri
fi
e
d
by
expe
ri
m
e
nt
at
i
o
n. The
pr
op
os
ed hy
b
r
i
d
M
L
I
t
opol
ogy
i
s
su
i
t
e
d fo
r f
u
el
cel
l
appl
i
cat
i
ons.
W
i
t
h
t
h
i
s
dual
re
fere
nce
P
W
M
t
e
c
hni
qu
e o
f
hy
bri
d
M
L
I, i
t
i
s
po
ssi
bl
e
t
o
co
nst
r
uct
hi
gh
p
o
w
er
d
r
i
v
e
s
wi
t
h
hi
gh
o
u
t
put
v
o
l
t
a
ge a
n
d l
o
w
TH
D.
Evaluation Warning : The document was created with Spire.PDF for Python.
&
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
1
,
No
.
2
,
D
ecem
b
er
2
011
:
10
4 – 112
11
2
Refere
nces
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Rashid M. H
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004.
Power Electronics:
Cir
c
uits, Devices, and
Applications, 3
rd
edition
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e-Hall
[2]
Ca
rra
sc
o J.
M,
e
t
a
l
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,
“ Powe
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s
t
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tegration
of Ren
e
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Choi N. S, et a
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,
“
A General Ci
rcuit Topo
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verter
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EE
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roni
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Calais M, e
t
al
.,
“
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nal
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sis of Multic
arri
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M
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eve
l
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,
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e
c
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cs
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M
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e
r
t
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e
feren
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a
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Calais
M., et al., “ A cascaded
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r
merless single p
h
ase grid
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onnected pho
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[9]
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r Multil
evel
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rter
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dustrial
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.,
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., “
S
witchi
ng losses and harm
onic investiga
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el inver
t
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[1
1]
P
a
rk S
.
J., et
al.
,
“
A
New S
i
ngle-P
h
ase F
i
ve
-Leve
l
P
W
M Inverter Em
plo
y
in
g a Deadbea
t
C
ontrol S
c
hem
e
”
,
IEEE
Transactions on
Power Electron
ics, 18
(18), 831-
843, 2003
.
[1
2]
ww
w.
m
a
th
w
o
r
k
s.
co
m
Ackn
owledge
ment
Th
e au
thors
wish
to express th
eir gratitu
de to
t
h
e
m
a
n
a
g
e
m
e
n
t
o
f
SSN
In
stitu
tion
s
, Ch
en
n
a
i, Ind
i
a for
p
r
ov
id
ing
t
h
e l
a
b
o
ratory and
co
m
p
u
t
atio
n
a
l
facilities to
carry ou
t th
is
wo
rk
.
B
i
bl
i
ogra
p
h
y
of
au
th
ors
Dr. R.
Se
yez
h
ai
o
b
t
a
i
n
e
d
her B
.
E
.
El
ec
t
r
o
n
i
c
s & C
o
m
m
uni
cat
i
on En
gi
neeri
n
g
)
f
r
om
No
or
ul
I
s
l
a
m
C
o
l
l
e
ge o
f
E
n
g
i
neeri
n
g,
Na
ge
rcoi
l
i
n
19
9
6
a
nd
he
r M
.
E i
n
Po
wer El
ect
r
o
ni
cs
& D
r
i
v
es
f
r
o
m
Shanm
ugha
C
o
l
l
e
ge
of
E
ngi
neeri
n
g
,
T
h
anja
v
u
r
i
n
19
9
8
a
n
d
P
h
.D
f
r
o
m
Anna
Uni
v
ersi
ty, Chennai. She ha
s bee
n
workin
g in t
h
e teaching field
for
a
b
out 13 Ye
ars.
Sh
e
h
a
s
pu
b
lish
e
d sev
e
ral
p
a
p
e
rs in
In
tern
at
io
n
a
l Jou
r
n
a
ls
an
d In
tern
ational Co
nferen
ces in
the area of Power Electronic
s
& Drive
s
. Her ar
eas of inte
rest include SiC Powe
r De
vices,
Mu
ltilev
e
l In
verters, M
o
d
e
li
n
g
o
f
fuel cells,
Design
of In
terleav
e
d
Bo
o
s
t Conv
ert
e
r,
Mu
ltilp
o
r
t
DC-DC Conv
erter
an
d con
t
ro
l tech
n
i
q
u
e
s for
DC-DC C
o
nv
erter.
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