Internati
o
nal
Journal of P
o
wer Elect
roni
cs an
d
Drive
S
y
ste
m
(I
JPE
D
S)
V
o
l.
6, N
o
. 3
,
Sep
t
em
b
e
r
2015
, pp
. 52
4
~
53
7
I
S
SN
: 208
8-8
6
9
4
5
24
Jo
urn
a
l
h
o
me
pa
ge
: h
ttp
://iaesjo
u
r
na
l.com/
o
n
lin
e/ind
e
x.ph
p
/
IJPEDS
Modeling and Simulation of Sup
erconducting Magnetic Energy
Storage Systems
Ashwin
K
u
m
a
r
Sahoo*, Nalinikan
ta Moh
a
nty**, An
upri
y
a
M*
* Departm
e
nt
of
Ele
c
tri
cal
and
E
l
ectron
i
cs
Eng
i
ne
er
ing, SSN College of
Engin
eerin
g, Chenn
a
i, Ind
i
a
** Departmen
t
o
f
Electr
i
cal
and
Electroni
cs
Eng
i
neering
,
S
V
CE,
Chennai
,
Ind
i
a
Article Info
A
B
STRAC
T
Article histo
r
y:
Received Apr 9, 2015
Rev
i
sed
Ju
l 15
,
20
15
Accepte
d
J
u
l 30, 2015
This paper aims to model the
Supe
rconducting
Magnetic
Ener
g
y
Storag
e
S
y
stem
(SMES) using various P
o
wer Condition
i
ng S
y
stem
s (PCS) such as,
Th
y
r
istor based
PCS (Six-pulse convert
er
and Twelve-pulse con
v
erter) and
Voltage Source
Converter (VSC) base
d PCS. Modeling and Simulation of
Th
y
r
istor based
PCS and VSC
b
a
sed PCS has been carr
i
ed out.
Comparison
has also been
carried out based
on vari
ous
cr
it
er
ia s
u
ch
as
Tot
a
l
Harm
onic
Dis
t
ortion (THD), act
ive and re
a
c
tiv
e power cont
rol abili
t
y
, con
t
r
o
l s
t
ructure
and power hand
ling capacity
.
MATLAB/Si
m
u
link is used to
sim
u
late th
e
various Power C
onditioning
S
y
stems of SMES.
Keyword:
Ener
gy
St
ora
g
e
Po
wer C
o
ndi
t
i
oni
ng
Sy
st
em
s
SMES
Th
yristor
VSC
Copyright ©
201
5 Institut
e
o
f
Ad
vanced
Engin
eer
ing and S
c
i
e
nce.
All rights re
se
rve
d
.
Co
rresp
ond
i
ng
Autho
r
:
A
s
hw
in Ku
m
a
r
Sahoo
,
Depa
rt
m
e
nt
of
El
ect
ri
cal
and
El
ect
roni
cs
E
n
gi
nee
r
i
n
g,
SSN
C
o
l
l
e
ge
o
f
E
ngi
neeri
n
g
,
OM
R
,
Kal
a
va
k
a
m
-
60
3
1
1
0
,
C
h
en
nai
,
I
ndi
a.
Em
a
il: ash
w
in
sah
oo@ssn
.
ed
u.in
1.
INTRODUCTION
A
Sup
e
r
c
o
nductin
g
Mag
n
e
ti
c En
er
g
y
Sto
r
ag
e
(
S
MES)
dev
i
ce is a
d
c
cu
rr
en
t
d
e
v
i
ce th
at stor
es
ener
gy
i
n
t
h
e
m
a
gnet
i
c
fi
el
d
.
The
dc cu
rre
nt
fl
o
w
i
n
g t
h
r
o
u
g
h
a su
perc
on
d
u
ct
i
ng
wi
r
e
i
n
a l
a
rge
m
a
gnet
creates the
m
a
gnetic
field.
Gen
e
rally it con
s
ists of:
Sup
e
r
c
on
du
ctin
g co
il
C
r
y
oge
ni
c sy
st
em
Po
wer C
o
nve
rs
i
on/
C
o
n
d
i
t
i
oni
ng
Sy
st
em
(PC
S
)
wi
t
h
c
o
nt
rol
an
d
pr
ot
ect
i
o
n
f
unct
i
o
ns.
The total efficiency of a SME
S
syste
m
can be ve
ry
hi
g
h
si
n
ce i
t
does
not
r
e
qui
re ene
r
gy
con
v
e
r
si
o
n
from
elec
trical
to m
echanical
or
c
h
em
i
c
al
energy
.
Depe
n
d
i
ng
on t
h
e co
nt
r
o
l
l
o
o
p
o
f
i
t
s
p
o
we
r co
n
v
ersi
on
uni
t
and s
w
itching
characte
r
istics, the SMES syste
m
can resp
ond
v
e
ry rap
i
d
l
y (M
W
s
/m
il
lisec
o
n
d
s
). Th
e ab
il
ity o
f
in
j
ecting
/
ab
sorb
ing
real o
r
re
active power c
a
n increase the
effectiven
e
ss of t
h
e co
nt
r
o
l
,
and e
nha
nce s
y
st
em
reliab
ility an
d
av
ailab
ility. Co
n
s
equ
e
n
tly, SMES h
a
s inh
e
re
n
tly
h
i
gh
sto
r
ag
e
efficien
cy
ab
ou
t 90
% o
r
g
r
eater
r
oun
d tr
ip
ef
f
i
cien
cy.
C
o
m
p
ari
ng wi
t
h
ot
he
r st
or
ag
e t
echnol
ogi
es
,
t
h
e SM
ES t
echn
o
l
o
gy
has a
uni
q
u
e ad
va
nt
age i
n
t
w
o
typ
e
s of ap
p
licatio
n
s
:
Power system
transm
ission
con
t
ro
l and
stab
ilizatio
n
Power qu
ality
im
p
r
o
v
e
m
e
n
t
.
For i
n
stance,
SMES can be
configure
d
to provi
d
e energy storage for
Flex
ib
le AC Tran
sm
issio
n
Sy
st
em
s (FAC
TS) co
nt
r
o
l
l
e
rs
at
t
h
e t
r
ansm
issi
on l
e
vel
o
r
cust
om
powe
r
d
e
vi
ces at
t
h
e di
st
ri
but
i
o
n l
e
vel
.
The
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
6, No
. 3, Sep
t
em
b
e
r
2
015
:
52
4 – 537
52
5
efficien
cy an
d fast respon
se
cap
ab
ility o
f
a SMES can
b
e
furth
e
r ex
p
l
o
ited
in
d
i
fferent ap
p
licatio
ns
in
all
levels of electric powe
r syste
m
s [1], [2].
1.1. Need
for SMES
Sup
e
rcon
du
ctiv
ity, th
e to
tal l
ack
o
f
resistance of
cond
uctin
g m
a
terials b
e
lo
w critical tem
p
eratu
r
es, is
o
n
e
of
th
e m
o
st f
a
scin
ating
p
h
e
no
m
e
n
a
in
n
a
tur
e
.
A
lth
oug
h
Sup
e
r
c
ondu
ctiv
ity w
a
s
d
i
scov
er
ed
in
191
1
b
y
Onn
e
s, it was
n
o
t
u
n
til 197
0s SMES
was fi
rst p
r
o
p
o
s
ed
as
a tech
no
log
y
in
power
system
s. En
erg
y
is sto
r
ed
in
t
h
e m
a
gnet
i
c
fi
el
d
gene
rat
e
d
by
ci
rc
ul
at
i
n
g
t
h
e
DC
cu
rre
nt
t
h
ro
u
g
h
a su
per
c
o
n
duc
t
i
ng c
o
i
l
.
SM
ES i
s
a
tech
no
log
y
th
at h
a
s th
e
p
o
t
ential to
b
r
ing
essen
tial fun
c
tion
a
l ch
aracteristics to
th
e u
tility tran
sm
issio
n
and
distribution sys
t
e
m
s [3], [4].
A SM
ES
sy
st
em
consi
s
t
s
of a
su
perc
o
n
d
u
ct
i
n
g
co
il, the cry
oge
nic system
,
and the
powe
r conve
rsi
on
or
co
n
d
i
t
i
oni
n
g
sy
st
em
(PC
S
)
wi
t
h
c
ont
rol
a
n
d
pr
ot
ect
i
o
n
f
u
nct
i
o
n
s
.
Ad
va
nt
ages
o
f
SM
ES ove
r ot
her
ene
r
gy
st
or
age
sy
st
em
:
The total efficiency can
be very
hi
g
h
si
nce
i
t
does n
o
t
re
q
u
i
r
e e
n
er
gy
co
nve
rsi
o
n f
r
o
m
one
fo
rm
t
o
t
h
e
ot
he
r.
Dep
e
nd
ing
on
its p
o
wer co
nversion
un
it’s co
n
t
ro
l loop
and switc
hing characteristics, the SMES system
can
respond ve
ry ra
pidly (M
Ws/m
illiseconds).
Because
of its
fast res
p
onse a
n
d its efficienc
y
, SMES
system
s have recei
ved c
o
nsidera
b
l
e
attention from
electric u
tilitie
s and
t
h
e
g
o
v
e
rn
m
e
n
t
.
SM
ES sy
st
em
s are
rel
i
a
bl
e (
n
o m
ovi
n
g
part
s
)
a
n
d
en
vi
r
onm
ent
a
l
l
y
beni
gn
.
C
o
m
p
ared t
o
o
t
her st
ora
g
e t
e
chn
o
l
o
gi
es, t
h
e
SM
ES t
ech
n
o
l
ogy
has a
u
n
i
q
ue a
dva
nt
age
i
n
t
w
o t
y
pe
s
o
f
ap
p
lication
,
p
o
wer system tran
smissio
n
con
t
ro
l and stab
ilizatio
n
an
d
po
wer quality. Alth
o
ugh
SMES
syste
m
s
m
a
y n
o
t
b
e
co
st effectiv
e, at th
e
p
r
esen
t tim
e,
th
e
y
h
a
v
e
a po
sitiv
e co
st. SMES’ efficien
cy and
fast
respon
se cap
a
b
ility h
a
s b
e
en
an
d
can
b
e
furth
e
r exp
l
o
i
t
e
d
in
d
i
fferen
t
app
licatio
n
s
i
n
all lev
e
l of
electric
p
o
wer syste
m
s
.
SMES system
s
h
a
v
e
th
e cap
a
b
ility o
f
pro
v
i
d
i
ng
; ov
erall en
h
a
n
ce secu
rity an
d
reliab
ility o
f
p
o
wer systems. Th
e ch
aracteristics o
f
po
ten
tial SM
E
S
ap
pl
i
cat
i
ons
fo
r
gene
rat
i
o
n, t
r
a
n
sm
i
ssi
on, a
n
d
di
st
ri
b
u
t
i
o
n
are
gi
ve
n i
n
Ta
bl
e
1.
Tab
l
e
1
.
C
h
aracteristics o
f
poten
tial
SMES ap
p
lication
s
in
p
o
wer system
s
1.
2. SME
S
T
e
chnol
ogi
es
In
SMES syst
e
m
s, it
is
th
e p
o
wer cond
itio
n
i
ng
system (PCS) that handles the power tra
n
sfe
r
betwee
n t
h
e s
u
perc
onducting
coil and t
h
e ac
syste
m
. The
r
e
are m
a
ny topologies a
v
ailabl
e for the
purpose of
char
gi
n
g
a
n
d d
i
schar
g
i
n
g of
S
M
ES.
Som
e
of t
h
e te
chnologies a
r
e,
Th
yristor-b
a
sed
PCS
Vol
t
a
ge
s
o
u
r
ce
co
nve
rt
er
(
V
S
C
)-
based
PC
S
Th
e Th
yristor-b
a
sed
SMES can
con
t
ro
l m
a
i
n
ly th
e activ
e p
o
wer, and
h
a
s a litt
le ab
ilit
y t
o
con
t
ro
l th
e
reactive powe
r; also the cont
rols of
act
i
v
e a
nd
react
i
v
e p
o
w
ers a
r
e n
o
t
i
n
depe
n
d
ent
.
O
n
t
h
e ot
he
r ha
nd
, bot
h
t
h
e VSC
-
an
d C
S
C
-
base
d
SM
ES can
cont
rol
bot
h
act
i
v
e and
re
act
i
v
e po
we
rs
i
nde
pen
d
e
n
t
l
y
and
si
m
u
ltan
e
o
u
s
ly
. Th
erefore, t
h
e app
licatio
ns in
wh
ich
main
ly th
e acti
v
e po
wer contro
l is req
u
i
red
,
th
e
th
yristo
r-b
a
sed SMES is used
,
wh
ile th
e ap
p
lication
s
in wh
ich
reactiv
e
po
wer or b
o
t
h
activ
e
and
reactiv
e
po
we
r c
ont
r
o
l
s
are
req
u
i
r
e
d
,
th
e
VSC-Based SMES is
u
s
ed
.
In t
h
i
s
p
a
per
secti
on 2 d
e
al
s wit
h
t
h
e b
a
si
c co
ncepts of
SMES. The
mo
d
e
l
i
n
g
of Thy
r
ist
o
r
based
SMES
has been dealt
in secti
on 3.The
m
odel
i
ng of Vol
t
age Sour
ce C
onverter based SM
ES has been di
scu
ssed
i
n
secti
on
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Mo
del
i
n
g
a
n
d
Si
m
u
l
a
t
i
o
n
of
S
upe
rco
n
duct
i
n
g M
a
gnet
i
c
E
n
ergy
St
or
a
g
e
S
y
st
ems
(Ash
win Ku
ma
r Sah
oo
)
52
6
4. The co
m
p
ar
ison bet
w
een Thy
r
ist
o
r based
SM
ES
and Vo
lt
ag
e Source
C
o
nvert
er b
a
sed SM
ES has been
done i
n
secti
on
5. The result
of t
h
e
pr
oject
has
been su
m
m
a
r
i
sed i
n
fi
nal
secti
on
6
.
It further
discu
sses abou
t
the f
u
ture
scope of
t
h
e wo
rk.
2.
SUPE
RC
ON
DU
CTI
N
G M
A
G
N
ETIC
E
N
ERGY STORAGE
SYST
EM
A SMES de
vi
ce is a dc current de
vice that stores
en
ergy in
th
e
m
a
g
n
e
tic field
.
Th
e d
c
cu
rren
t
f
l
ow
ing
th
rou
g
h
a su
p
e
r
c
ondu
ctin
g
w
i
r
e
i
n
a lar
g
e m
a
g
n
et cr
eates th
e
mag
n
e
tic f
i
eld [
3
]. Th
e inductiv
el
y
s
t
o
r
ed
e
n
er
g
y
(
E
i
n
Jo
ul
e) a
nd t
h
e
rat
e
d
p
o
we
r (
P
in
Watt) are co
mmo
n
l
y g
i
ven
sp
ecificatio
n
s
fo
r
SMES
devi
ces
,
E
1
2
LI
(1
)
P
dE
dt
L
I
dI
dt
(2
)
whe
r
e,
L
-
Inductance
of the c
o
il
I
- D
C
cur
r
e
n
t
f
l
ow
ing
thr
ough
th
e co
il
V
- Vo
ltag
e
acro
ss th
e co
il
A SM
ES
sy
st
em
consi
s
t
s
of a
su
perc
o
n
d
u
ct
i
n
g
co
il, the cry
oge
nic system
,
and the
powe
r conve
rsi
on
or conditioni
ng syste
m
(PCS) with control and
protection functions
. IEEE
defines SMES
as “A
sup
e
rc
on
d
u
ct
i
n
g m
a
gnet
i
c
en
ergy
st
o
r
a
g
e d
e
vi
ce co
nt
ai
ni
ng el
ect
r
o
ni
c c
o
n
v
e
r
t
e
rs t
h
at
rapi
dl
y
i
n
ject
s
and/
or
abs
o
rbs real
a
n
d/or
reacti
v
e powe
r or
dy
namically controls
powe
r fl
ow in
an ac
system
”.
Suc
h
a
de
vice
has a
num
ber o
f
ad
v
a
nt
age
o
u
s
an
d
uni
q
u
e c
h
arac
t
e
ri
st
i
c
s:
No con
v
e
r
si
o
n
o
f
ener
gy
fr
om
one form
t
o
anot
her i
s
req
u
i
r
e
d
;
co
ns
eque
nt
l
y
SM
ES has i
n
he
rent
l
y
hi
gh st
ora
g
e efficiency,
a 90%
or great
er
round tri
p
efficiency.
D
e
p
e
nd
ing
o
n
th
e pow
er conv
er
si
o
n
un
it’
s
co
n
t
r
o
l l
o
op
a
n
d switc
hing c
h
aracteristics, the SME
S
devi
ce ca
n
resp
o
nd
very
r
a
pi
dl
y
(M
W
s
/
m
i
ll
i
s
econd
s) t
o
p
o
we
r de
m
a
nds
fr
om
m
a
xi
m
u
m
charge t
o
m
a
xim
u
m
di
schar
g
e.
SMES systems can of
fer ver
y
r
e
liab
l
e an
d long
lif
e
time service. E
x
cept
for cer
t
a
in
designs, they are
co
nsid
er
ed
to
be env
i
ro
n
m
en
tally b
e
n
i
gn
syste
m
s [
5
],
[6
],
[7
].
2.
1. C
o
mp
one
n
ts of
S
M
E
S
As ca
n
be see
n
f
r
o
m
Fi
gure
1,
a SM
E
S
s
y
st
em
connect
ed t
o
a
po
we
r
sy
st
em
consi
s
t
s
of
sev
e
ral
su
bsystem
s
[
4
]. A
lar
g
e
su
per
c
on
d
u
ct
i
ng c
o
i
l
is
th
e h
eart of th
e SMES syste
m
s.
It is
contained in a cryostat
or
de
war
t
h
at
c
onsi
s
t
s
o
f
a
va
cuum
vessel
a
n
d c
ont
ai
n
s
l
i
q
u
i
d ve
ssel
t
h
at
c
ool
s
t
h
e c
o
i
l
.
A
cry
o
genic sy
stem
is
to
k
e
ep
t
h
e temp
erat
u
r
e
well
belo
w t
h
e criti
cal te
m
p
erature
for the
s
upe
rconductor.
An ac/dc
po
wer con
versi
o
n
or cond
itio
n
i
ng
system
(PC
S
)
i
s
use
d
fo
r t
w
o
pu
r
poses:
O
n
e is to conver
t
fr
o
m
d
c
to
ac
To c
h
ar
ge a
n
d
di
scha
rge
t
h
e
c
o
i
l
.
Fi
gu
re
1.
C
o
m
p
o
n
e
n
t
s
of a
t
y
pi
cal
SM
ES
sy
st
em
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em
b
e
r
2
015
:
52
4 – 537
52
7
A
tran
sfo
r
mer
p
r
o
v
i
d
e
s th
e
co
nn
ection
to
th
e po
wer syst
e
m
an
d
redu
ces th
e op
erating
vo
ltag
e
t
o
acceptable le
ve
ls for t
h
e PCS.There
is two
t
y
pes of
s
upe
rco
n
d
u
ct
o
r
s
u
s
ed
t
o
form
a SMES co
il:
Low
Tem
p
er
atu
r
e Su
p
e
r
c
ondu
ctor
s
(
LTS)
H
i
gh
Tem
p
er
at
u
r
e Su
p
e
r
c
ondu
ctor
s
(
H
TS)
A com
posi
t
e
o
f
al
l
o
y
s
o
f
Ni
obi
um
and Ti
t
a
ni
um
(Nb
-
Ti
)
cop
p
e
r
i
s
u
s
e
d
m
o
st
com
m
onl
y
f
o
r l
o
w
t
e
m
p
erat
ure
su
perc
o
n
d
u
ct
o
r
s
(LTS
).
The
H
T
S m
a
t
e
ri
al
i
s
, at
p
r
ese
n
t
,
b
i
sm
ut
h-st
r
ont
i
u
m
-
cal
ci
u
m
coppe
r
-
oxi
de
(B
SC
C
O
).
Du
ri
n
g
SM
E
S
o
p
e
r
at
i
o
n
,
t
h
e m
a
gnet
coi
l
s
has t
o
rem
a
i
n
s
upe
rc
on
d
u
ct
i
n
g.
A
refrig
era
t
or
in
th
e
cry
o
g
e
n
i
c system m
a
in
tain
s the requ
ired
tem
p
eratu
r
e fo
r th
e pro
p
e
r
superc
onducting
operation. T
h
e
refrige
r
ation l
o
ad can
affect the
ove
rall efficie
n
cy and c
o
st
of a
SMES
sy
st
em
. Theref
ore
,
t
h
e
ref
r
i
g
erat
i
on l
o
ad
t
h
at
has l
o
ss
co
m
ponent
s,
suc
h
as c
o
l
d
t
o
w
a
rm
current
l
e
ads,
a
c
cu
rr
en
t, co
nductio
n
and
r
a
d
i
atio
n
,
shou
ld
b
e
m
i
n
i
mized
to
ach
iev
e
a h
i
gher
ef
f
i
cien
t and
less co
stly S
M
ES
syste
m
.
Any a
b
norm
al condition t
h
a
t
m
a
y cause a safety
hazard to personnel or
dam
a
ge to the m
a
gnet
sho
u
l
d
be
det
ect
ed an
d
p
r
ot
ec
t
e
d t
h
ro
u
g
h
t
h
e
m
a
gnet
pr
ot
ec
t
i
on sy
st
em
.
A
PCS
provi
des a power el
ectronic interface betwee
n ac power syste
m
and the superconducting
co
il. It allows t
h
e SMES system
to
resp
ond
with
in
ten
s
o
f
mil
liseco
n
d
s to po
wer
d
e
m
a
n
d
s
t
h
at cou
l
d in
clud
e
a chan
ge f
r
om
m
a
xim
u
m
ch
arge
rat
e
t
o
m
a
xi
m
u
m
di
sc
harge
po
we
r. T
h
i
s
rapi
d res
p
ons
e al
l
o
ws a
di
u
r
nal
sto
r
ag
e
un
it to
p
r
ov
id
e sp
i
n
n
i
n
g
reserv
e an
d
i
m
p
r
ov
e system
stab
il
ity. Th
e conv
erter / SMES system
is
h
i
gh
ly
efficient, as t
h
ere is no ene
r
gy co
n
v
ersi
on
f
r
om
one f
o
rm
t
o
an
ot
he
r. C
o
nve
rt
ers m
a
y
pro
d
u
ce ha
rm
oni
cs on
th
e ac
b
u
s an
d
in
th
e term
in
al
v
o
ltag
e
of t
h
e
co
il. Us
ing
higher pulse c
o
nverters ca
n
reduce these
harm
onics.
Th
e sup
e
rcon
du
ctin
g co
il is ch
arg
e
d
o
r
d
i
sch
a
rg
ed
b
y
m
a
k
i
n
g
t
h
e
v
o
ltag
e
across th
e co
il
po
sitiv
e or
negat
i
v
e
.
The c
o
il absorbs power
from the ac syste
m
and acts as
a l
o
ad
duri
ng
one
half cycle when the c
o
nve
r
te
r
v
o
ltag
e
is
p
o
s
it
iv
e.
Duri
ng the
ne
xt hal
f
cycle, t
h
e c
o
il operates as a
ge
ner
a
t
o
r se
ndi
ng
po
we
r
back
i
n
t
o
t
h
e
ac sy
st
em
s when
th
e conv
erter
vo
ltag
e
is m
a
d
e
n
e
g
a
tiv
e.
W
h
en
t
h
e
un
it is on
stan
db
y
,
ind
e
p
e
nd
en
t
o
f
stor
ag
e level, th
e cu
rren
t is
constant
, a
n
d the a
v
e
r
age
vol
t
a
ge
acr
oss
t
h
e s
upe
rco
n
d
u
c
t
i
ng
wi
n
d
i
n
g i
s
zer
o.
A PCS c
o
uld
be either a current s
o
urce i
n
verter
or
a
voltage s
o
urce inve
rter
with
a dc-dc
c
h
oppe
r
in
terface [8
].
3.
THYRISTOR BASE
D SME
S
In SME
S
syste
m
s, Thyristor based PCS is
one of
th
e power co
nd
itio
n
i
n
g
system
th
at
h
a
nd
les th
e
powe
r tra
n
sfe
r
betwee
n t
h
e
SMES a
n
d the
ac system
.
Th
e th
y
r
isto
r b
a
sed
SMES can
co
n
t
ro
l m
a
i
n
ly the
active powe
r,
and
has a littl
e ability to control the r
eact
ive powe
r. M
o
re
over, t
h
e c
ont
rols
of active and
reactive powers are
not inde
pende
nt. T
h
e
r
efore
,
the a
p
pli
catio
n
s
in
wh
ich
m
a
in
ly th
e activ
e po
wer con
t
ro
l is
r
e
qu
ir
ed
, t
h
yr
isto
r
b
a
sed
SMES is used [9
-11].
The t
h
y
r
i
s
t
o
r
-
b
ased
PC
S ca
n
be i
m
pl
em
ent
e
d
by
usi
n
g,
Six
p
u
l
se
conver
t
er
Twelve
pulse c
o
nve
r
ter
Th
e
wo
rk
ing
of
six pu
lse and
tw
elv
e
p
u
l
s
e
co
nv
er
te
r
ar
e
a
s
f
o
llow
s
:
3.
1.
Ch
argi
n
g
and
Di
sch
a
r
g
i
n
g
of
S
M
E
S
u
s
i
n
g Si
x P
u
l
s
e
Co
nver
ter
Fi
gu
re 2, sh
o
w
s
t
h
e basi
c
c
o
n
f
i
g
urat
i
o
n of
a
t
h
y
r
istor-b
a
sed
SMES
u
n
it,
wh
ich
co
nsists o
f
a
W
y
e-
Delta tran
sformer, an
ac/d
c
t
h
yristor con
t
rolled
b
r
i
d
g
e
conv
erter, and
a su
p
e
rco
ndu
cting
co
il or ind
u
c
to
r [5
].
The c
o
n
v
ert
e
r
im
presses p
o
si
t
i
v
e or
ne
gat
i
v
e vol
t
a
ge
o
n
t
h
e supe
rc
on
d
u
ct
i
ng c
o
i
l
.
C
h
ar
g
e
and
di
sc
har
g
e are
easily co
n
t
ro
lled
b
y
sim
p
ly ch
an
g
i
n
g
th
e
d
e
lay an
g
l
e t
h
at con
t
ro
ls th
e
sequen
tial firing
o
f
th
e th
yristors.
If
α
is less th
an 90
, t
h
e co
nv
erter op
erat
es in
th
e rectifier mo
d
e
(ch
a
rg
ing)
If
α
is
greater t
h
an 90, the c
onv
erter op
erates in
th
e inv
e
rter
m
o
d
e
(d
isch
arg
i
ng
)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
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S
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8-8
6
9
4
Mo
del
i
n
g
a
n
d
Si
m
u
l
a
t
i
o
n
of
S
upe
rco
n
duct
i
n
g M
a
gnet
i
c
E
n
ergy
St
or
a
g
e
S
y
st
ems
(Ash
win Ku
ma
r Sah
oo
)
52
8
Fi
gu
re
2.
B
a
si
c ci
rcui
t
of t
h
e t
h
y
r
i
s
t
o
r
based
SM
ES
As a result, power can
be abs
o
rbe
d
from
or rel
eased to the
power system
according to requi
rem
e
nt.
At the
steady s
t
ate, SMES s
h
oul
d
not
c
o
ns
ume
any
real or reactive powe
r.
Th
e vo
ltag
e
of
t
h
e dc
si
de
o
f
t
h
e c
o
n
v
e
r
t
e
r i
s
exp
r
esse
d
by
,
cos
(
3
)
Whe
r
e,
is th
e id
eal no-lo
ad
max
i
m
u
m
d
c
vo
ltag
e
of t
h
e
b
r
i
d
g
e
.
The c
u
r
r
e
n
t
an
d
vol
t
a
ge
o
f
s
u
perc
o
n
du
cting
in
du
ctor are rel
a
ted
as,
1
(4
)
Whe
r
e,
is th
e i
n
itial cu
rren
t
of th
e ind
u
c
t
o
r.
The real
power,
P
abs
o
r
b
ed
o
r
del
i
v
ere
d
by
t
h
e SM
ES ca
n
be
gi
ve
n
by
,
P
V
I
(
5
)
The e
n
er
gy
st
o
r
ed
i
n
t
h
e s
upe
rco
n
duct
i
n
g i
n
duct
o
r
i
s
(6
)
whe
r
e,
is th
e in
itial en
erg
y
in th
e indu
ctor.
Th
is is app
licab
le fo
r th
e t
w
el
v
e
p
u
l
se conv
erter also
[5
].
Sin
ce th
e br
idge cur
r
e
n
t
I
is not rev
e
rsib
le, the bridg
e
o
u
t
p
u
t
po
wer
P
is un
iqu
e
ly a fun
c
tio
n o
f
,
wh
ich
can
b
e
p
o
s
itiv
e
or n
e
gativ
e
d
e
p
e
n
d
i
ng
o
n
V
. I
f
V
is po
sitiv
e, power is
tr
an
sferred from
th
e p
o
wer
syste
m
to
th
e SMES un
it.
Wh
i
l
e if
V
is n
e
g
a
tiv
e, power is released
fro
m
th
e SMES un
it.
3.
2.
Si
mul
a
ti
o
n
o
f
T
h
yri
s
t
o
r
B
a
sed
S
M
E
S
usi
n
g
Si
x
Pul
s
e C
o
n
v
erter
The
T
h
y
r
i
s
t
o
r base
d
SM
ES
u
s
i
ng Si
x Pul
s
e
C
o
n
v
er
ter is si
m
u
la
ted
in
M
A
TLAB/Sim
u
l
in
k
as sh
own
in
Figu
re
3
.
Th
e SMES co
il is ch
arg
e
d
from t=0
s
to
t=0
.
1
6
s
by
ap
pl
y
i
n
g
t
h
e Fi
ri
ng a
n
gl
e
α
=30
0
.
The
SMES
cu
rren
t is m
a
in
tain
ed
con
s
tan
t
fro
m
t=0
.
16
s
t
o
t=0.32
s
by
a
ppl
y
i
n
g
t
h
e Fi
r
i
ng a
n
gl
e
α
=90
0
. Th
e SMES co
il is
di
scha
rge
d
f
r
o
m
t
=
0.32
s
to
t=0
.
4
8
s
by applying the Firing angle
α
=150
0
. The Firing Angle circuit of the
Th
yr
istor
b
a
sed
SMES is show
n in
Figu
r
e
4. Th
e Ou
tpu
t
wav
e
fo
r
m
is show
n in
Figu
r
e
5.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
6, No
. 3, Sep
t
em
b
e
r
2
015
:
52
4 – 537
52
9
Fi
gu
re
3.
C
i
rcu
i
t
of t
h
y
r
i
s
t
o
r
b
a
sed
SM
ES
usi
n
g
si
x
p
u
l
s
e c
o
nve
rt
ers
Fi
gu
re
4.
Fi
ri
n
g
a
ngl
e ci
rcui
t
Fi
gu
re
5.
O
u
t
p
ut
v
o
l
t
a
ge
an
d
Out
put
c
u
rre
nt
fo
r t
h
y
r
i
s
t
o
r
ba
sed SM
E
S
usi
n
g si
x
pul
se c
o
n
v
ert
e
r
s
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Mo
del
i
n
g
a
n
d
Si
m
u
l
a
t
i
o
n
of
S
upe
rco
n
duct
i
n
g M
a
gnet
i
c
E
n
ergy
St
or
a
g
e
S
y
st
ems
(Ash
win Ku
ma
r Sah
oo
)
53
0
3.
3.
Si
mul
a
ti
o
n
o
f
T
h
yri
s
ter
base
d
SMES using
Twelve
Pulse
Conver
ter
Th
e Th
yr
ist
o
r
b
a
sed
SMES
usin
g Tw
el
v
e
Pu
lse C
onv
erter is sim
u
lated
in
MATLAB/Si
m
u
lin
k
as
sho
w
n i
n
Fi
gu
re 6.
The
SM
E
S
coi
l
i
s
char
g
e
d f
r
om
t
=
0
s
to
t=0
.
16
s
by
a
ppl
y
i
n
g
t
h
e Fi
r
i
ng a
ngl
e
α
=30
0
. The
SMES curren
t
is
m
a
in
tain
ed
co
n
s
tan
t
fro
m
t=0
.
1
6
s
to
t=0
.
32
s
by
ap
pl
y
i
ng
t
h
e Fi
ri
ng a
n
g
l
e
α
=90
0
. T
h
e
SMES
coi
l
i
s
di
schar
g
ed f
r
o
m
t
=
0.32
s
to
t=0.48
s
by
appl
y
i
ng t
h
e Fi
ri
n
g
an
gl
e
α
=150
0
. The
Out
p
ut
W
a
ve
fo
rm
i
s
sho
w
n i
n
Fi
gu
r
e
7.
Fi
gu
re
6.
C
i
rcu
i
t
of t
h
y
r
i
s
t
o
r
b
a
sed
SM
ES
usi
n
g
t
w
el
ve
p
u
l
s
e co
nve
rt
ers
Fi
gu
re
7.
O
u
t
p
ut
v
o
l
t
a
ge
an
d
Out
put
c
u
rre
nt
fo
r t
h
y
r
i
s
t
o
r
ba
sed SM
E
S
usi
n
g t
w
el
ve
pul
se
con
v
e
r
t
e
rs
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
6, No
. 3, Sep
t
em
b
e
r
2
015
:
52
4 – 537
53
1
4.
VOLTA
GE S
O
U
RCE
CO
N
V
ERTER BASED SMES
In SM
ES sy
st
em
s, Vol
t
a
ge
So
urce C
o
n
v
er
t
e
r (VSC
) bas
e
d PC
S i
s
one
of t
h
e p
o
w
er
con
d
i
t
i
oni
n
g
syste
m
s that handles the
power tr
a
n
s
f
er
between the SMES and t
h
e ac syste
m
. The VSC-base
d SMES can
co
n
t
ro
l bo
th
activ
e
and
reactiv
e po
wers
i
n
dep
e
nd
en
tly
an
d
si
m
u
l
t
a
neousl
y
. The
r
ef
o
r
e,
whi
l
e
t
h
e a
ppl
i
cat
i
ons
in which react
ive powe
r or
bot
h activ
e and reactive
power controls are
require
d
, the
VSC-base
d SMES is
use
d
[
7
]
.
Fi
g
u
r
e
8 s
h
ows
t
h
e
basi
c c
o
nfi
g
u
r
at
i
o
n
o
f
t
h
e
VSC
-
base
d
S
M
ES u
n
i
t
,
w
h
i
c
h c
o
nsi
s
t
s
o
f
a
W
y
e-
Del
t
a
t
r
ans
f
or
m
e
r, a si
x
-
pul
se p
u
l
s
e
wi
dt
h
m
odul
at
i
on
(
P
W
M
)
rect
i
f
i
e
r (
o
r
)
i
nve
rt
er
usi
n
g
i
n
s
u
l
a
t
e
d
gat
e
bi
p
o
l
a
r t
r
a
n
si
st
or
(I
GB
T
)
, a
t
w
o
-
q
u
a
d
ra
nt
d
c
-dc
ch
o
ppe
r
u
s
i
ng
I
G
B
T
, a
n
d a s
u
perc
o
n
d
u
c
t
i
ng c
o
i
l
o
r
i
n
duct
o
r
[
5
]. Th
e PW
M
co
nv
er
ter
an
d
th
e d
c
-
d
c chopp
er
ar
e link
e
d
b
y
a d
c
li
n
k
cap
acito
r. Th
e PW
M VSC pr
ov
id
es a
powe
r electronic interface
bet
w
een the ac
power
sy
st
em
and t
h
e
s
upe
rco
n
duct
i
n
g c
o
i
l
[
8
-1
1]
.
Fi
gu
re
8.
B
a
si
c co
nfi
g
u
r
at
i
o
n
of
VSC
-
ba
sed
SM
ES sy
st
em
The S
u
perc
o
n
d
u
ct
i
n
g
coi
l
i
s
c
h
ar
ge
d o
r
di
sc
har
g
e
d
by
a
t
w
o-
q
u
ad
ra
nt
dc
-
d
c c
h
o
p
p
er
(C
l
a
ss D C
h
op
pe
r
)
.
In Class D cho
p
p
e
r
v
o
ltag
e
ch
an
g
e
s are
b
o
t
h
p
o
sitiv
e
an
d n
e
g
a
tiv
e,
b
u
t
t
h
e cu
rrent is m
a
in
tain
ed
constant.
Th
e
d
c
-d
c ch
op
p
e
r is co
n
t
ro
l
l
ed
to
su
pp
ly
p
o
s
itiv
e
(IGB
T is tu
rn
ed ON)
o
r
n
e
g
a
tiv
e (IGBT is turned
OFF
)
v
o
l
t
a
ge
t
o
SM
ES coi
l
and t
h
en t
h
e s
t
ore
d
ene
r
gy
c
a
n be c
h
ar
ged
or di
sc
har
g
e
d
. Ther
ef
ore
,
t
h
e
sup
e
rc
on
d
u
ct
i
n
g coi
l
i
s
c
h
ar
g
e
d o
r
di
scha
rg
ed by
a
d
j
u
sting
th
e av
erag
e
v
o
ltag
e
acro
ss
th
e co
il wh
ich
is
determ
ined by
the duty cycle
of
t
h
e t
w
o
-
q
u
a
d
ra
nt
dc-
d
c c
h
op
pe
r.
Whe
n
t
h
e duty
cycle is larger than
0.5
or less tha
n
0.5, the sto
r
ed
en
ergy o
f
t
h
e coil is
either c
h
arging/
di
scha
rgi
n
g
.
In
ord
e
r to
g
e
nerate th
e PW
M
g
a
te sig
n
a
ls for th
e IGBT
of the choppe
r, the refere
nce signal is com
p
ared
with
th
e triangu
lar si
g
n
a
l.
4.1. Simulation
of Vol
t
age
Source Converter
Based SME
S
M
odel
i
n
g
of
V
o
l
t
a
ge S
o
urce
C
o
n
v
ert
e
r
base
d SM
E
S
have
t
w
o
i
m
port
a
nt
c
i
rcui
t
s
:
Co
n
t
ro
l Circu
it
Ch
opp
er
Cir
c
uit
The
VSC
base
d SM
E
S
i
s
si
m
u
l
a
t
e
d i
n
M
A
T
L
AB
/
S
i
m
ul
i
nk as s
h
o
w
n i
n
Fi
gu
re
9.
T
h
e c
o
nt
r
o
l
ci
rc
ui
t
of
VSC
i
s
s
h
o
w
n
i
n
Fi
g
u
re
1
0
a
n
d
t
h
e c
h
op
per
ci
rcui
t
i
s
sh
ow
n i
n
Fi
gu
re
11
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Mo
del
i
n
g
a
n
d
Si
m
u
l
a
t
i
o
n
of
S
upe
rco
n
duct
i
n
g M
a
gnet
i
c
E
n
ergy
St
or
a
g
e
S
y
st
ems
(Ash
win Ku
ma
r Sah
oo
)
53
2
Fi
gu
re 9.
V
S
C
base
d
SM
E
S
Figu
re
1
0
. C
o
n
t
rol circ
uit
Fi
gu
re
1
1
. C
h
o
ppe
r ci
rc
ui
t
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
6, No
. 3, Sep
t
em
b
e
r
2
015
:
52
4 – 537
53
3
4.
2. Resul
t
An
al
ysi
s
o
f
VSC
B
a
sed SME
S
The
VSC
base
d SM
ES i
s
si
m
u
l
a
t
e
d and t
h
e res
u
l
t
s
are
obt
ai
ne
d.
The
SM
ES coi
l
i
s
char
ge
d f
r
om
t=0
s
to
t=0
.
65
s
by
a
ppl
y
i
n
g
t
h
e
dut
y
cy
cl
e
of
ch
o
ppe
r as
70
%. T
h
e
SM
ES i
s
f
u
l
l
y
cha
r
ge
d
wh
en t
=
0
.
4
s
and
th
e co
nstan
t
cu
rren
t fl
o
w
s throug
h
th
e SM
ES co
il. Th
e SMES co
il is d
i
sch
a
rg
ed
at t=
0
.
6
5
s
by
appl
y
i
ng t
h
e
d
u
t
y cycle o
f
ch
opp
er
as
2
0
%. Th
e
V
o
ltag
e
acr
o
s
s SMES,
Cu
rr
en
t thr
ough
SMES an
d
Vo
ltag
e
acro
ss
V
S
C is
sho
w
n i
n
Fi
gu
re
12
. T
h
e
V
o
l
t
a
ge acr
oss
S
M
ES, C
u
r
r
ent
t
h
r
o
ug
h
SM
E
S
a
n
d
V
o
l
t
a
ge
acr
oss
VSC
du
ri
n
g
char
gi
n
g
i
s
s
h
o
w
n i
n
Fi
g
u
re
1
3
. T
h
e V
o
l
t
a
ge
across
SM
ES,
C
u
rr
ent
t
h
ro
u
gh
SM
ES a
nd
Vol
t
a
ge ac
r
o
ss
VS
C
du
ri
n
g
di
scha
r
g
i
n
g i
s
s
h
ow
n
i
n
Fi
g
u
r
e
14
.
The
V
o
l
t
a
ge a
c
ross
SM
ES
,
C
u
r
r
ent
t
h
r
o
u
g
h
SM
E
S
a
n
d
Vol
t
a
g
e
acros
s V
S
C
a
f
t
e
r
di
scha
rgi
n
g
i
s
sh
ow
n i
n
Fi
g
u
re
1
5
.
Fig
u
re
12
.
Vo
ltag
e
acro
ss SM
ES, cu
rren
t th
ro
ugh
SMES,
vo
ltag
e
acro
ss
VSC
Fi
gu
re
1
3
.
V
o
l
t
a
ge ac
ros
s
SM
ES, c
u
r
r
e
n
t
t
h
r
o
u
g
h
SM
E
S
,
v
o
l
t
a
ge ac
ros
s
VSC
du
ri
n
g
c
h
argi
ng
0
0.
1
0.
2
0.
3
0.
4
0.
5
0.
6
0.
7
0.
8
0.
9
1
-
100
0
-5
0
0
0
50
0
10
00
Ti
m
e
(
s
)
O
u
t
put
V
o
l
t
age(
V
)
O
u
tp
u
t
Vo
lt
a
g
e
V
s
T
i
m
e
0
0.
1
0.
2
0.
3
0.
4
0.
5
0.
6
0.
7
0.
8
0.
9
1
0
20
40
60
Ti
m
e
(
s
)
O
u
t
put
c
u
r
r
ent
(
A
)
O
u
tp
u
t
c
u
r
r
e
n
t V
s
T
i
m
e
0
0.
1
0.
2
0.
3
0.
4
0.
5
0.
6
0.
7
0.
8
0.
9
1
-
200
0
200
400
600
800
Ti
m
e
(
s
)
v
o
l
t
ag
e a
c
r
o
s
s
V
S
C
(
V
)
v
o
lt
a
g
e
a
c
r
o
s
s
VS
C
Vs
T
i
m
e
0.
1
8
0.
1
8
5
0.
19
0.
19
5
0.
2
0.
2
0
5
0.
21
0.
215
0.
22
-
400
-
200
0
200
400
Ti
m
e
(
s
)
O
u
t
put
V
o
l
t
a
ge(
V
)
O
u
t
put
V
o
l
t
age
V
s
T
i
m
e
0.
18
0.
185
0.
19
0.
195
0.
2
0.
205
0.
21
0.
215
0.
2
2
0
20
40
60
Ti
m
e
(
s
)
O
u
t
p
u
t
c
u
rr
e
n
t
(A
)
O
u
tp
u
t
c
u
r
r
e
n
t
V
s
T
i
m
e
0.
18
0.
18
2
0.
184
0.
1
8
6
0.
188
0.
19
0.
192
0.
194
0.
1
9
6
0.
198
0.
2
0
200
400
600
Ti
m
e
(
s
)
v
o
l
t
a
ge a
c
r
o
s
s
V
S
C
(
V
)
v
o
l
t
age ac
r
o
s
s
V
S
C
V
s
T
i
m
e
Evaluation Warning : The document was created with Spire.PDF for Python.