Internati
o
nal
Journal of P
o
wer Elect
roni
cs an
d
Drive
S
y
ste
m
(I
JPE
D
S)
Vol
.
6
,
No
. 2,
J
une
2
0
1
5
,
pp
. 37
6~
38
6
I
S
SN
: 208
8-8
6
9
4
3
76
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
Open-Delta VSC Based Voltage
Controller in Isolated Power
Systems
Shilpi Bhat
ta
cha
r
y
a
*
,
Pra
b
al D
e
b*
*, Suj
i
t
Biswa
s
*
*
*
,
Amba
rnat
h B
a
nerj
ee*
***
* Department of
Electrical Eng
i
n
eering
,
RCC
Institute of
Informat
ion Technolog
y
,
India
** Departmen
t
o
f
Electr
i
cal
Engineering
,
Gu
ru N
a
nak Institute of
Techno
log
y
, Ind
i
a
***Department
of Electr
i
cal
Eng
i
neer
ing, Jadavp
ur University
, In
dia
****Department of Electrical En
gineer
ing, Megh
nad Saha Inst
itute of
Technolog
y
,
India
Article Info
A
B
STRAC
T
Article histo
r
y:
Received
Ja
n 31, 2015
Rev
i
sed
Mar
28
, 20
15
Accepted Apr 20, 2015
This pap
e
r pro
poses a redu
ced switc
h vo
ltag
e
source conv
erter (VSC)
topolog
y
implemented as
a vo
ltage contro
ller in isolated pow
er
s
y
stems. In
isolated power
s
y
stems generally
self
-
e
xcited induction gen
e
rators (SEIG)
are used
mainly
for
their rug
g
edne
ss and
economic reasons. Mostly
for
constant power
applications
such as pico h
y
dro
uncontrolled turbine driven
s
e
lf exc
ited
ind
u
ction gen
e
ra
tor
s
feeding thr
ee-
phas
e
loads
ar
e
em
plo
y
ed
.
The proposed r
e
duced switch
voltag
e
c
ontroller is used to
r
e
gulate
and
control
the vo
lt
age
at th
e g
e
ne
rator t
e
rm
inals
as it
is subjec
te
d to vol
tag
e
drops, dips or flickers when
the
isolated
pow
er s
y
stem is subjected to var
i
ous
criti
ca
l loads. In
this paper the c
ontro
lle
r is
reali
zed us
i
ng a three-leg four-
switch insulat
e
d
gate bipo
lar tr
ansist
or (IGBT) based curren
t
controlled
voltag
e
-source
converter
(CC-VSC) and
a self-supporting dc bu
s contain
i
ng
two split cap
aci
t
ors, thus reducing th
e IGBT
count and hen
c
e cost. Th
is
reduced switch topolog
y
forms an Open
-Delta type converter. Th
e proposed
generating s
y
stem along with t
h
e contro
ller is modeled and simulated in
MATLAB along
with Simulink
and power
s
y
stem blockset (PSB) toolboxes
.
The s
y
s
t
em
is
s
i
m
u
lated a
nd the
capab
ili
t
y
of th
e
is
olat
ed gen
e
ra
t
i
ng s
y
s
t
em
along with the reduced switch
based vo
ltag
e
controller is presented her
e
where th
e g
e
ner
a
tor f
eeds
linear
and non-linear loads are inv
e
stig
ated
.
Keyword:
Asy
n
c
h
r
o
no
us gene
rat
o
r
Op
en-Delta VSC
PCC
R
e
newa
bl
e e
n
e
r
gy
s
o
urces
Vo
ltag
e
con
t
roller
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
:
Sh
ilp
i B
h
attach
arya,
Depa
rt
m
e
nt
of
El
ect
ri
cal
Engi
neeri
n
g
,
RCC Institut
e
of
Inform
ation
Technolog
y
,
C
a
nal
S
out
h R
o
ad
, B
e
l
i
a
g
h
at
a, Kolkata
70
01
07
, Ind
i
a
Em
a
il: sh
ilp
ib
hatt2
0
13@g
m
ai
l.co
m
1.
INTRODUCTION
In
rem
o
t
e
l
o
cat
i
ons, i
s
ol
at
ed
gene
rat
i
n
g
uni
t
s
are
bei
n
g
us
ed t
o
ex
pl
oi
t
t
h
e e
n
er
gy
a
v
ai
l
a
bl
e fr
om
r
e
n
e
w
a
b
l
e en
er
g
y
sour
ces na
m
e
ly so
lar
,
hyd
ro
or
w
i
nd. These isolate
d
power syste
m
s
are dedica
ted to
p
r
ov
id
e electri
cal p
o
wer
within
a sm
all lo
cal g
r
i
d
sited
in
far-flung
v
illag
e
s
o
r
in in
accessib
l
e h
illy terrains.
As the transm
ission c
o
sts are
high, these local powe
r
syste
m
s are a cost effective option a
nd ca
n be
set-up
wi
t
h
m
odest
eff
o
rt
. S
u
c
h
m
i
cro
or sm
al
l
isol
at
ed p
o
w
er
net
w
or
ks ge
n
e
ral
l
y
com
p
ri
ses of a sel
f
-e
xci
t
e
d
i
n
d
u
ct
i
on
gen
e
rat
o
r
s
(SE
I
G
)
dri
v
en
by
pri
m
e
m
overs de
ri
vi
n
g
t
h
ei
r en
ergy
f
r
om
non
-co
n
v
ent
i
o
nal
sou
r
ces
.
The induction m
achine being the obvi
ou
s choice in suc
h
system
s because of
its low cost, rugge
d
brushles
s
co
nstru
c
tion
,
small size, lo
w
main
ten
a
n
ce an
d self
sh
ort
ci
rcui
t
pr
ot
ect
i
o
n.
The
asy
n
c
h
r
o
n
o
u
s m
achi
n
e
w
h
e
n
running as a generat
o
r a
r
e se
lf excited
by a capacitor
b
a
nk
conn
ected
acro
ss its term
in
als [1
-8
].
A d
e
tailed
revi
e
w
an
d co
m
p
ari
s
on i
s
pr
esent
e
d i
n
[9]
.
These i
s
ol
at
ed
po
we
r net
w
or
k
s
are vul
nera
bl
e t
o
vol
t
a
ge sa
g, di
p
o
r
flick
e
r du
e
to
v
a
riou
s co
nsu
m
er lo
ad
con
d
ition
s
su
ch
as: sud
d
e
n
in
crease in
l
o
ad
,
u
n
b
a
lan
c
ed
l
o
ad
s and
n
on-
lin
ear
l
o
ad
s co
nn
ected
t
o
th
e pow
er
n
e
tw
or
k. In
su
c
h
a case the
SE
IG
operation i
s
subjected t
o
une
ve
n
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
.
2,
Ju
ne 20
15
:
376
–
3
86
3
77
heat
di
st
ri
b
u
t
i
o
n a
n
d e
v
en
t
o
r
que
ri
ppl
es
an
d as
a
res
u
lt operates
at a
de
-rated
leve
l w
h
ich fu
rther af
fe
cts the
q
u
a
lity o
f
power at th
e g
e
n
e
rato
r term
in
als
wh
ich
is also
th
e po
in
t of commo
n
co
up
ling
(PCC)
for o
t
h
e
r lo
ad
s
in
th
e iso
l
ated syste
m
. To
t
a
k
e
care
o
f
such
a
s
itu
atio
n
i.e to
im
p
r
ov
e th
e
q
u
a
lity of po
wer and
sup
p
l
y
sufficient react
ive power t
o
t
h
e syst
em
, the m
o
st effective solution is t
h
e
use
of a DST
A
TCOM as
cited
by
vari
ous
a
u
t
h
or
s
i
n
[
1
0
-
1
6
]
.
DST
A
TC
OM
gene
rat
e
d
r
eac
tive power caters t
o
the
re
quirem
ent of sa
me as
dem
a
nded by
powe
r system
and its loa
d
s.
More
ove
r it
re
duce
s
the
react
ive
power demande
d by t
h
e c
a
pacitor
ban
k
(co
n
n
ect
ed at
ge
nerat
o
r t
e
rm
i
n
al
s for
exci
t
a
t
i
on)
t
o
i
t
s
no
-l
oa
d l
e
vel
[
17]
.
DST
A
TC
OM
’s are
po
w
e
r
electro
n
i
c conv
erters, b
i
d
i
rectio
n
a
l in
its
fun
c
tion
and
are ab
le to
serv
e m
u
ltip
le
p
u
rp
o
s
es
o
f
vo
ltag
e
r
e
gu
latio
n, su
pp
r
e
ss eff
ect of p
oor
pow
er
facto
r
o
f
l
o
ads
on
powe
r syst
e
m
s, re
duce effects of unbalance
d
l
o
adi
n
g an
d al
so l
o
a
d
l
e
vel
i
n
g (i
f s
o
m
e
energy
st
o
r
i
n
g co
m
ponent
s are
pr
o
v
i
d
e
d
).
Gen
e
ral
l
y
a DSTA
TC
OM
is realized
usin
g
a curren
t
co
n
t
ro
lled
VSC
co
m
p
risin
g
o
f
six
power swi
t
ch
es, a
DC bu
s cap
acito
r an
d
filter
inductors in ea
ch line.
The
ob
ject
i
v
e
of t
h
e
pape
r i
s
t
o
use
a re
d
u
ce
d s
w
i
t
c
h
co
nv
er
te
r
topo
log
y
(f
ou
r-
sw
itc
h
)
ch
r
i
s
t
e
n
ed
as
Op
en-Delta (on
e
co
nv
erter leg
d
e
vo
id of act
iv
e switche
s)
vo
ltag
e
so
ur
ce
co
nv
er
ter
(
O
D-
VSC)
to
per
f
o
r
m
the
t
a
sk o
f
a si
x
swi
t
c
h D
S
T
A
TC
OM
. T
h
i
s
r
e
duce
d
s
w
i
t
c
h
con
v
ert
e
r t
o
p
o
l
o
gy
has
bee
n
use
d
i
n
n
u
m
ber of
research
work
s, m
a
j
o
rity o
f
wh
ich
is
in the a
r
ea of m
achine dri
v
es for i
ndu
ctio
n m
o
to
r
dr
iv
es
[
1
8
]
, an
d
m
o
r
e
recently in brushless BLDC dri
v
es as in [19-20] and in
s
y
nchronous motor dri
v
es
[21]. In view of its low
con
v
e
r
t
e
r c
o
st
,
beca
use
of
re
duce
d
re
qui
r
e
m
e
nt
of
swi
t
c
h
e
s,
heat
si
n
k
a
n
d
d
r
i
v
e
r
ci
rc
u
i
t
r
y
,
t
h
i
s
t
o
p
o
l
ogy
has
g
e
n
e
rated m
u
ch
in
terest am
o
n
g
th
e au
t
h
ors
to
u
tilize it as a vo
ltag
e
con
t
roller for au
tonom
o
u
s
po
w
e
r sy
ste
m
s.
Th
us, t
h
i
s
pa
p
e
r p
r
o
p
o
ses a
n
appl
i
cat
i
o
n ar
ea fo
r t
h
e l
o
w
cost
re
duce
d
s
w
i
t
c
h co
n
v
ert
e
r t
o
pol
ogy
f
o
r
vol
t
a
ge
regu
latio
n
ag
ain
s
t tran
sien
t fl
u
c
tu
ation
s
in
vo
ltag
e
p
r
ofile u
n
d
e
r v
a
ri
o
u
s
lo
ad
ing
cond
itio
n
s
o
ccurri
n
g
in
an
of
f-
gri
d
i
s
ol
at
e
d
po
wer
sy
st
em
. Thi
s
OD
-V
SC
t
o
p
o
l
o
gy
c
o
m
p
ri
ses o
f
f
o
ur a
c
t
i
v
e s
w
i
t
c
hes i
n
st
ead
of
si
x a
n
d
t
w
o
num
bers
o
f
capaci
t
o
rs at
t
h
e DC
bus
[1
8-
2
9
]
.
The c
o
s
t
of sem
i
cond
u
c
t
o
r,
heat
si
n
k
and
d
r
i
v
er ci
rc
ui
t
i
s
red
u
ce
d by
1/
3
rd
due t
o
c
h
a
nge
d t
o
pol
ogy
of t
h
e co
n
v
er
t
e
r ci
rcui
t
.
Th
e i
s
ol
at
ed di
st
r
i
but
i
o
n sy
st
em
un
der
st
udy
has t
h
e
f
o
l
l
o
wi
ng
com
pone
nt
s:
a
SEI
G
t
h
ri
vi
ng
o
n
con
s
t
a
nt
po
wer
del
i
v
e
r
ed
by
a
m
i
cro-
hy
d
r
o
t
u
r
b
i
n
e
and a
n
O
D
-
V
SC
cont
r
o
l
l
e
r
wi
t
h
a bat
t
e
ry
ener
gy
st
ora
g
e syste
m
(BE
SS) at the DC
side. The
OD-VSC
cont
rol
l
e
r t
a
ke
s care of
vol
t
a
ge fl
i
c
ke
rs, d
r
ops a
n
d sags
occu
rri
ng i
n
t
h
e po
wer
di
st
ri
but
i
o
n sy
st
em
due t
o
vari
ous l
o
adi
n
g co
n
d
i
t
i
ons
. I
n
a co
nst
a
nt
s
p
eed t
u
r
b
i
n
e
d
r
i
v
i
n
g t
h
e a
s
y
n
ch
r
o
n
o
u
s f
r
e
que
ncy
i
s
m
a
int
a
i
n
ed
con
s
t
a
nt
d
u
e t
o
const
a
nt
s
p
ee
d of
pri
m
e
m
o
ver
.
In t
h
is p
a
per, th
e syste
m
is si
m
u
lated
in
MATLAB Si
m
u
l
i
n
k
Versi
on
7.
9 w
h
i
c
h c
o
m
p
ri
ses of a
n
O
D
-
V
S
C
cont
r
o
l
l
e
r co
nnect
e
d
at
t
h
e PC
C
,
wh
ere
p
o
we
r i
s
ge
nera
t
e
d b
y
th
e SEIG
f
e
d
by a co
n
s
tan
t
pow
er
inpu
t. Th
e effectiv
en
ess
o
f
th
e
OD-VSC b
a
sed
co
n
t
roller is v
a
lid
ated
wit
h
si
m
u
latio
n
resu
lts for v
a
ri
ou
s typ
e
s of co
nn
ected
lo
ads: a) Balanced Linear
and n
o
n
-
lin
ear load
s b)
Unbalance
d
Linear and
Non-linear l
o
ads
.
2.
POWER SYSTEM LAYOUT
Th
e layou
t o
f
t
h
e pow
er
system is
depi
ct
ed i
n
Fi
g
u
re
1.
It
com
p
ri
ses of a t
h
ree
-
phase asy
n
chronous
gene
rat
o
r d
r
i
v
e
n
by
a co
nst
a
n
t
speed p
r
i
m
e-m
over. The
ge
nerat
e
d p
o
we
r
i
s
del
i
v
ere
d
t
o
t
h
e de
di
cat
ed po
we
r
d
i
stribu
tio
n sy
ste
m
(iso
lated
fro
m
th
e
m
a
in
g
r
i
d
)
with
va
rious
cons
um
er loads s
u
ch as
balanced, unbal
anced,
lin
ear an
d
/
o
r
no
n-lin
ear.
Three
star c
o
nnected static ca
pac
i
t
o
rs
are al
s
o
p
r
ovi
ded
f
o
r
sup
p
l
y
i
n
g t
h
e
no
-l
oa
d e
x
ci
t
i
ng cu
rre
nt
o
f
th
e asyn
chr
onou
s g
e
n
e
r
a
t
o
r. Th
e OD
-V
SC B
E
SS typ
e
con
t
ro
ller
is as sh
ow
n, con
n
ected
in
shu
n
t
to
th
e
p
o
w
e
r
net
w
or
k at
t
h
e
p
o
i
n
t
of
c
o
m
m
on co
upl
i
n
g
i
n
Fi
g
u
r
e
1.
F
o
u
r
p
o
we
r-s
wi
t
c
hes
(I
GB
T’s
)
a
n
d
t
w
o ca
p
aci
t
o
rs
form
th
e
main
p
o
wer circu
it o
f
th
e con
t
ro
ll
er. Th
e DC bus co
n
s
ists
o
f
t
w
o
sp
lit cap
acito
r, th
e m
i
d
p
o
in
t o
f
whic
h is c
o
nnected to one
phase
of the
AC side.
A BE
SS is con
n
ected
acro
ss th
e DC bu
s.
Th
e b
a
ttery is
m
o
d
e
led
with
a p
a
rallel co
mb
in
ation
of a co
n
s
i
d
erab
ly h
i
g
h
v
a
lu
e capacito
r (C
B
) and a
resistance (R
B
) and a
sm
a
l
l value series resistance (R
s
). Thi
s
bat
t
e
r
y
serves as a powe
r
so
urce
du
ri
n
g
ope
rat
i
o
n of t
h
e D
S
TA
T
C
OM
as a curre
n
t-controlled volta
ge source inve
rter. T
h
e AC si
de terminal
s
o
f
th
e
OD
-V
S
C
co
nf
igu
r
ed
co
nv
e
r
ter
terminals are c
o
nnected to the SEIG term
in
als. Three filter react
ors with
inductance L
f
and resistance
R
f
are
use
d
to re
plicate the e
ffect
of
a
of the
transform
e
r inducti
ve
reactance
a
s
that of a
practica
l
system
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Ope
n
-Del
t
a
VS
C
Base
d V
o
l
t
a
ge C
ont
r
o
l
l
e
r i
n
Isol
at
ed
Pow
e
r Syst
e
m
s
(Sh
ilp
i Bha
tta
ch
arya
)
37
8
Fi
gu
re
1.
P
o
we
r Sy
st
em
Lay
out
di
a
g
ram
of
t
h
e i
s
ol
at
ed
po
wer
sy
st
em
3.
OPERATIONAL CONT
ROL STRATEGY
The m
a
i
n
aim of a v
o
l
t
a
ge and
fre
que
ncy
cont
r
o
l
l
e
r i
s
t
o
re
gul
at
e t
h
e
vol
t
a
ge
of a p
o
we
r sy
st
em
u
n
d
e
r sev
e
re lo
ad
i
n
g cond
itio
n
s
. M
o
re precisely it is u
s
ed to c
ontrol the reactive
power fl
ow (i
nject
ed
or
abs
o
rbed) in a
powe
r system
and c
o
ns
e
que
ntly keep a chec
k on the term
in
al vo
ltag
e
at th
e po
in
t
o
f
commo
n
cou
p
l
i
n
g (
P
C
C
) w
h
i
c
h i
s
t
h
e c
o
m
m
on di
st
ri
but
i
o
n
p
o
i
n
t
t
o
vari
o
u
s c
ons
um
er l
o
ads
.
The
VSC
sy
st
em
i
s
commanded (by its controll
er) t
o
absorb
reactive
powe
r if it sees its termin
al v
o
l
t
a
g
e
rises abov
e th
e
p
r
escrib
ed
v
a
l
u
e
wh
ereas it
in
j
ects
reactiv
e po
wer in
t
o
the syste
m
wh
en th
e vo
ltag
e
dro
p
s
. In
t
h
is p
a
p
e
r a
r
e
du
ced
sw
itch PW
M co
nv
er
ter
OD
-V
SC
is
co
n
t
ro
lled
t
o
deliv
er th
e sim
i
l
a
r attribu
t
es of a con
v
e
n
tion
a
l six
swi
t
c
h
DST
A
T
C
OM
. L
o
ad
ba
l
a
nci
n
g
,
l
o
a
d
l
e
vel
i
n
g
an
d
ha
rm
oni
c red
u
ct
i
o
n
f
unct
i
o
ns a
r
e al
so c
ont
ri
b
u
t
ed by
t
h
e re
d
u
ced
sw
i
t
c
h sol
i
d
-st
a
t
e
cont
rol
l
e
r.
T
h
e
co
nt
rol
schem
e
sh
ow
n i
n
Fi
g
u
re
2 c
o
m
p
ri
ses o
f
t
w
o
out
e
r
l
o
o
p
s
fo
r v
o
l
t
a
ge c
o
nt
r
o
l
:
one f
o
r
m
a
i
n
t
a
i
n
i
ng D
C
bus
vol
t
a
ge
and t
h
e ot
h
e
r f
o
r m
oni
t
o
ri
ng
t
h
e AC
si
de t
e
rm
i
n
al
voltage
of the
VSC. T
h
e
dire
ct axis curre
nt
refe
rence
(
I
gdref
), the acti
v
e curre
nt com
p
one
n
t, is ge
ne
rated from
t
h
e DC
b
u
s
v
o
l
t
age er
r
o
r
p
r
oc
essed t
h
r
o
ug
h
a PI
co
nt
r
o
l
l
e
r
bl
oc
k.
The
DC
b
u
s
v
o
l
t
a
ge
(
V
dc
) is essen
tially th
e
sum
of t
h
e i
n
di
vi
d
u
al
vol
t
a
ges ac
ross
the
capacitors C
1
and C
2
as re
prese
n
ted in Figure 1. T
h
e reactive
current c
o
m
p
onent
(
I
gqref
) is ob
tain
ed after
p
r
o
cessing
t
h
e error
o
f
th
e
AC sid
e
term
in
al v
o
ltag
e
at th
e
PCC.
Fi
gu
re
2.
C
o
nt
r
o
l
bl
ock
di
a
g
ra
m
AC
si
de t
e
rm
inal
vol
t
a
ge (
V
t(a
c
)
r
e
f
)
i
s
set
at
a refere
nce val
u
e of
1 p.
u. T
h
e sy
nch
r
oni
z
a
t
i
on of t
h
e
positive
seque
n
ce
voltage
com
ponents
of the three
phase s
u
pply side
AC
voltages is ac
hieve
d
with the he
l
p
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
.
2,
Ju
ne 20
15
:
376
–
3
86
3
79
of a phase
-
loc
k
ed-loop (PLL
). The
t
h
r
e
e-
phase lin
e cu
r
r
e
nts o
f
th
e pow
er
syste
m
are se
nse
d
, m
easured, a
nd
finally convert
e
d to ‘d-a
xis’
and
‘q-a
xis’ c
o
m
pone
nts by
getting re
quir
ed sync
hronizing si
gnals
from
the
PLL. T
h
e c
u
r
r
e
nt
re
gul
at
o
r
s
gene
rat
e
s t
h
e
r
e
spect
i
v
e
d-a
x
i
s
vol
t
a
ge t
e
rm
V
d(
n
)
and q-a
x
i
s
vol
t
a
ge t
e
rm
V
q(
n
)
,
whi
c
h are
fe
d
t
o
t
h
e P
W
M
g
e
nerat
i
o
n
bl
oc
k.
As t
h
i
s
t
o
p
o
l
ogy
h
a
s f
o
ur
act
i
v
e p
o
we
r s
w
i
t
c
hes s
o
onl
y
fo
ur
P
W
M
si
gnal
s
are t
o
be
ge
ne
rat
e
d t
o
o
p
e
r
at
e t
hose
sw
itches in
a
fash
ion to
con
t
ro
l th
e reactiv
e
p
o
wer and
attain
zero vo
ltag
e
regu
latio
n.
4.
C
O
N
T
ROL ALGOR
ITHM
THEORY
Ass
u
m
i
ng t
h
e l
i
n
e vol
t
a
ge
s a
t
t
h
e gene
rat
o
r
t
e
rm
i
n
al
s t
o
b
e
pu
rel
y
si
nus
oi
dal
an
d
bal
a
nced t
h
ree
-
p
h
a
se AC
vo
ltag
e
s, t
h
e am
p
l
i
t
u
d
e
o
f
t
h
is vo
l
t
ag
e can
b
e
ob
tain
ed
fro
m
th
e th
ree lin
e-to-lin
e vo
ltag
e
s
v
ab
, v
bc
,
v
ca
and
t
h
us ca
n
be e
x
p
r
esse
d
as:
22
2
()
(2
/
3
)
(
)
ta
c
r
e
f
a
b
b
c
c
a
Vv
v
v
(1
)
The
q
u
ad
rat
u
r
e
com
pone
nt
o
f
de
si
re
d re
fer
e
nce s
o
urce c
u
rre
nt
i
s
c
o
m
put
ed f
r
om
t
h
e v
o
l
t
a
ge e
r
r
o
r
w
h
i
c
h i
s
di
ffe
re
nce bet
w
een t
h
e desi
r
e
d t
e
rm
i
n
al
vol
t
a
ge
V
t(
ac
)
r
ef
and
V
t(
n
)
,
t
h
e m
e
asure
d
vol
t
a
ge
a
t
n
th
in
stan
t o
f
th
e AC
source term
inal com
puted from equa
tio
n
i
n
(1
). Th
is
v
o
ltage erro
r
V
e
r
(n
)
at
t
h
e nt
h sam
p
l
i
ng i
n
st
ant
i
s
gi
ven i
n
(2
),
()
(
)
()
()
er
n
t
a
c
r
e
f
t
n
VV
V
(
2
)
The refe
ren
ce qua
d
r
at
ure
co
m
ponent
of
cu
r
r
ent
i
s
gi
ve
n b
y
,
()
(
1
)
(
)
(
1
)
(
)
g
qr
ef
n
g
qr
ef
n
p
a
e
r
n
er
n
i
a
e
r
n
II
K
V
V
K
V
(
3
)
K
pa
and
K
ia
in eq
uat
i
on (
3
)
are t
h
e pr
op
ort
i
o
nal
an
d i
n
t
e
g
r
al
gai
n
c
onst
a
nt
s of t
h
e out
er P
I
co
nt
r
o
l
l
e
r
(co
n
tr
oller ‘a’
)
.
V
er(
n
)
and
V
er(n-1)
are the vol
tage errors at
n
th
and
(n
-
1
)
th
in
stan
ts.
I
gqref(
n
-1)
i
s
t
h
e quad
r
at
ure
current c
o
m
p
on
ent at
(n-1)
th
in
s
t
a
n
t
.
The q
-
a
x
i
s
cu
rre
nt
of t
h
e s
y
st
em
i
s
deri
v
e
d af
ter se
nsi
ng the three
-
phase source currents a
nd
con
v
e
r
t
i
ng t
h
e
m
t
o
d-
q cu
rre
nt
s by
Pa
rk
’s t
r
ansf
o
r
m
a
ti
on.
Therea
ft
er t
h
e
I
gqref
and t
h
e ca
lculated q-axis
source
current are
fe
d into a curre
nt cont
roller
block as
sh
o
w
n
in Figu
re 2.
The cu
rre
nt er
ro
r at n
th
in
stan
t is
calculated as,
()
()
()
g
q
er
n
gqref
gq
n
II
I
(
4
)
Thi
s
cu
rre
nt
er
ro
r i
s
pr
ocesse
d t
h
r
o
ug
h a i
n
ner P
I
co
nt
r
o
l
l
e
r t
o
ge
nerat
e
t
h
e d-a
x
i
s
de
si
red
vol
t
a
ge
ref
e
renc
e
V
q(
n
)
gi
ven as
b
e
l
o
w i
n
(5
),
()
(
1
)
(
)
(
1
)
(
)
q
n
q
n
p
b
gqe
r
n
g
q
e
r
n
i
b
gqer
n
VV
K
I
I
K
I
(
5
)
K
pb
and
K
ib
are t
h
e pr
op
o
r
t
i
o
nal
and i
n
t
e
gra
l
gai
n
s fo
r t
h
e
i
nner P
I
co
nt
r
o
l
l
e
r (c
ont
r
o
l
l
e
r ‘b
’)
of t
h
e c
u
r
r
en
t
cont
rol
bl
oc
k.
To
m
a
in
tain
th
e DC b
u
s
v
o
l
t
a
g
e
at th
e referen
ce
DC b
u
s
v
o
ltag
e
level, th
e DC bu
s vo
l
t
ag
e erro
r is
com
put
ed as
i
n
(
6
) a
n
d t
h
i
s
er
ro
r
bei
n
g a
g
ai
n
fe
d t
o
a P
I
c
o
n
t
rol
l
e
r
bl
oc
k.
()
()
()
dcer
n
d
cr
e
f
d
c
n
VV
V
(
6
)
Fro
m
th
e DC v
o
ltag
e
erro
r ob
tain
ed
at an
y in
stan
t i.e sa
mp
led
at ‘n
’, th
e req
u
i
site in
-ph
a
se or activ
e cu
rren
t
com
pone
nt
I
gdr
ef(
n
)
at ‘n th sa
m
p
le tim
e can be
obtaine
d
as,
()
(
1
)
(
)
(
1
)
()
g
dr
e
f
n
gdref
n
p
a
d
cer
n
d
ce
r
n
i
a
dcer
n
II
K
V
V
K
V
(
7
)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Ope
n
-Del
t
a
VS
C
Base
d V
o
l
t
a
ge C
ont
r
o
l
l
e
r i
n
Isol
at
ed
Pow
e
r Syst
e
m
s
(Sh
ilp
i Bha
tta
ch
arya
)
38
0
K
pa
and
K
ia
are th
e p
r
o
portio
nal an
d
in
tegral g
a
in
s for th
e in
ner P
I
co
nt
r
o
l
l
e
r of t
h
e cu
rre
nt
co
nt
rol
l
e
r
.
T
h
e d
-
axis source c
u
rrent at the n
th
in
stan
t
I
gd(
n
)
as
obt
ai
ne
d aft
e
r Par
k
’s t
r
a
n
sf
o
r
m
a
t
i
on from
t
h
e sensed t
h
ree
-
pha
se
currents
of the
AC s
o
urce, is
use
d
to g
e
t t
h
e
d
-
ax
is cu
rren
t
erro
r
I
gder(
n
)
gi
v
e
n as
i
n
(8
),
(
)
()
()
()
g
de
r
n
gdref
n
g
d
n
II
I
(
8
)
I
gdref(
n
)
is the calculated
values
of re
fere
nce
c
u
rrent at t
h
e
n
th
in
stan
t.
()
(
1
)
(
)
(
1
)
()
d
n
d
n
p
b
gder
n
g
d
er
n
i
b
gder
n
VV
K
I
I
K
I
(
9
)
Th
e
d
-
ax
is
v
o
l
tag
e
is th
en
o
b
tain
ed
acco
r
d
i
n
g
to
(9) in the PI con
t
ro
ller as in
Fi
gu
re
2.
K
pb
and
K
ib
ar
e
th
e
pr
o
p
o
r
t
i
onal
an
d i
n
t
e
gral
gai
n
s f
o
r t
h
e i
nne
r
PI c
o
nt
rol
l
e
r
.
5.
PWM STRAT
E
GY
The P
W
M
st
ra
t
e
gy
i
s
si
nusoi
dal
pul
se
-wi
d
t
h
m
odul
at
i
on t
echni
que
, al
t
h
o
u
g
h
beca
use
of
t
h
e chan
ge
d
t
o
p
o
l
o
gy
o
f
t
h
e VSC
,
i
n
t
h
i
s
case, som
e
change
s nee
d
s t
o
be i
n
c
o
r
p
orat
e
d
. T
h
e m
odul
at
i
on i
n
de
x ‘m
’ and t
h
e
pha
se an
gl
e ‘
Φ
’ are com
put
ed from
V
d(
n)
and
V
q(
n)
whi
c
h has bee
n
de
ri
v
e
d at
(9
) an
d (
5
) re
spect
i
v
el
y
.
Fr
o
m
‘m
’ and
‘
Φ
’ t
h
e
desi
re
d si
n
u
soi
d
al
si
g
n
al
s
are
deri
ved
f
o
r
SP
W
M
co
nt
r
o
l
.
A
hi
gh
swi
t
c
hi
n
g
fre
q
u
enc
y
trian
g
u
l
ar
signal is u
s
ed
to
attain
t
h
e f
o
u
r
swi
t
c
hi
n
g
si
gn
al
s of t
h
e
IGB
T
’s.
The
co
nt
r
o
l
bl
ock
di
a
g
r
a
m
fo
r
i
m
p
l
e
m
en
tatio
n
of SPW
M
fo
r
Op
en
-Delta co
nv
erter is
d
e
pi
ct
ed i
n
Fi
g
u
re
3. T
h
e t
r
a
n
sf
orm
e
d si
gn
al
s from
refe
rence s
e
t o
f
v
o
ltages
v
1
, v
2
, v
3
as s
h
o
w
n
i
n
Fi
g
u
re
1 a
n
d gi
ven i
n
(
1
0)
t
h
r
o
u
g
h
(
1
2
)
a
r
e use
d
t
o
o
b
t
a
i
n
t
h
e
m
odul
at
i
ng wa
vef
o
rm
s for si
nus
oi
dal
P
W
M
.
Tw
o si
g
n
al
s (
v
1
- v
3
) a
nd
(
v
2
- v
3
) are
proce
ssed to ac
hieve two
sym
m
et
ri
cal
vol
t
a
ges re
fere
nce wa
ve
fo
rm
s fo
r p
h
ases
1 an
d
2 w
h
i
c
h are si
nu
soi
d
al
wave
fo
rm
s phas
e
di
spl
ace
d by
6
0
o
from
each ot
her with a
peak value
3
ti
m
e
s o
f
th
at of
d
e
sir
e
d ph
ase
vo
ltag
e
s.
6
3
0
1
10
t
Sin
V
v
v
v
m
(
1
0
)
2
3
0
2
20
t
Sin
V
v
v
v
m
(
1
1
)
0
0
3
30
v
v
v
(
1
2
)
Phase
-
3
co
nsi
s
t
s
o
f
no
co
n
t
rol
l
a
bl
e s
w
i
t
c
hes t
hus
t
h
e
r
e
fere
nce
wa
ve
fo
rm
for
the
third
p
h
ase
is zer
o
.
Su
bseq
ue
nt
l
y
the swi
t
c
hi
ng si
gnal
s
ca
n be
o
b
t
a
i
n
ed
by
co
n
v
ent
i
o
nal
com
p
ari
s
on
of t
h
e
refe
rence
wave
fo
rm
s
with a
high
fre
que
ncy tria
ngular carrier
wa
ve.
This technique
has excellent
feature
s
, like real-t
im
e cont
rol
an
d easi
l
y
obt
ai
ne
d
dri
v
e
si
gnal
s
, t
h
e
num
ber
of
swi
t
chi
n
g
’
s a
r
e
re
l
a
t
i
v
el
y
hi
gh
,
and
t
h
e
refe
re
nce si
gnal
s
h
o
u
l
d
be sy
nch
r
oni
ze
d t
o
t
h
e
carri
er
si
gnal
.
Fi
gu
re
3.
SP
W
M
co
nt
rol
o
f
O
p
en
-
D
el
t
a
v
o
l
t
a
ge s
o
urce c
o
n
v
ert
e
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. 6,
No
.
2,
Ju
ne 20
15
:
376
–
3
86
3
81
6.
DESIGN OF BESS
CONT
ROLLER
FOR OD-VSC
CONTROLLER
Fi
gu
re 1 s
h
ow
s t
h
e B
E
SS
w
h
ere t
h
e bat
t
e
r
y
has bee
n
m
odel
e
d
by
i
t
s
Th
eveni
n
’s e
q
ui
v
a
l
e
nt
ci
rcui
t
.
V
dc
is th
e DC
b
u
s
v
o
ltage, V
oc
i
s
t
h
e no
-l
oa
d o
p
en ci
rc
ui
t
vol
t
a
ge
of t
h
e
bat
t
e
ry
, R
s
is g
e
n
e
rally o
f
small v
a
lu
e
and i
s
t
h
e e
q
ui
val
e
nt
r
e
si
st
ance (e
xt
er
nal
and i
n
t
e
rnal
)
of t
h
e
bat
t
e
r
y
. The ene
r
gy
st
ora
g
e an
d
vol
t
a
ge
co
nd
itio
n during
ch
arg
i
ng
and d
i
sch
a
rg
ing
is
re
presen
ted
b
y
th
e p
a
rallel com
b
in
atio
n
of R
B
and C
B
. T
h
e
value
of R
B
i
s
l
a
rge
as t
h
e sel
f
di
schar
g
i
n
g c
u
r
r
e
nt
of a
ba
ttery is s
m
a
ll. Th
e d
c
bu
s vo
ltag
e
fo
r a six-switch
con
v
e
r
t
e
r sy
st
em
shoul
d be
g
r
eat
er t
h
a
n
pea
k
o
f
t
h
e r.m
.
s l
i
n
e v
o
l
t
a
ge at
t
h
e ac si
de f
o
r
pr
o
p
er o
p
e
r
at
i
on
of
th
e
VS
C.
F
o
r
w
o
r
k
ing
w
i
th
an
O
p
en-
D
e
lta
co
nv
er
te
r th
e termin
al v
o
ltag
e
o
f
b
a
ttery is
g
i
v
e
n b
y
,
22
2
3
rm
s
Bd
c
V
VV
m
(
1
3
)
‘m
’ i
s
t
h
e
m
odul
at
i
on i
n
de
x whi
c
h can ha
v
e
a
m
a
xim
u
m
val
u
e o
f
1
.
0
.
The l
i
n
e vol
t
a
ge
on t
h
e AC
si
d
e
of t
h
e
VSC is
V
rm
s
. The
e
q
ui
val
e
nt
capaci
t
a
nce
o
f
t
h
e
bat
t
e
ry
m
ode
l
can
b
e
math
e
m
atica
l
l
y
represen
ted b
y
(14
)
gi
ve
n bel
o
w,
3
22
ma
x
m
i
n
3600
10
0.
5
(
)
B
oc
o
c
kW
h
C
VV
(
1
4
)
whe
r
e V
ocm
a
x
and
V
ocm
i
n
are respect
i
v
el
y
t
h
e m
a
xim
u
m
and m
i
nim
u
m
ope
n ci
rc
ui
t
vol
t
a
ge
of t
h
e
bat
t
e
ry
du
ri
n
g
i
t
s
ope
r
a
t
i
on.
Ene
r
gy
s
t
ore
d
i
n
t
h
e
bat
t
ery
i
s
m
easured i
n
k
W
h
.
7.
MATL
AB
BA
SED MO
DEL
L
ING A
N
D
C
O
NTR
O
L
The e
n
t
i
r
e
sy
st
em
of
Fi
g
u
re
1
i
s
m
odel
e
d
i
n
M
A
TL
AB
7.
9
pl
at
f
o
rm
. Fo
r
w
ar
d E
u
l
e
r m
e
t
hod
o
f
in
teg
r
ation
is u
s
ed
for all in
tegratio
n
s
i
n
th
e PI con
t
ro
ller b
l
o
c
k
s
. Th
e d
i
screte ti
m
e
in
teg
r
ato
r
b
l
o
c
k
app
r
oxi
m
a
t
e
s 1/
s as T/
(Z
-1
),
whi
c
h
gi
ves
t
h
e ex
pres
si
o
n
f
o
r a
n
y
o
u
t
p
ut
at
n
th
sam
p
le ti
m
e
/step
Y(n) as,
()
(
1
)
Yn
Yn
K
T
*
U
(
n
-
1
)
(
1
5
)
A
15
kW
, 415
V, 50
H
z
,
4
-
p
o
l
e Y-
co
nn
ected
in
du
ction
mach
in
e is
mo
d
e
led
to
op
er
ate as an
in
du
ction
gene
rat
o
r an
d 5-
kV
AR
Y
-
co
nnect
e
d
exci
t
a
t
i
on capaci
t
o
r ba
nk
with
n
e
utral is co
n
n
ect
ed at the three-phas
e
term
inals. The
OD-
VSC BE
SS base
d DS
TATC
OM
is
con
n
ected
in
sh
un
t to
th
e AC d
i
strib
u
tion syste
m
t
h
r
o
u
g
h
t
r
a
n
sf
orm
e
r im
peda
nce L
f
, R
f
. The asyn
chro
nous g
e
n
e
r
a
t
o
r
f
e
ed
s
v
a
r
i
o
u
s
con
s
u
m
er
s and
t
h
u
s
is
exp
o
se
d t
o
l
i
n
ear,
no
n-l
i
n
ea
r
,
bal
a
nce
d
a
n
d
un
-bal
a
n
ce
d l
o
ad
s. T
h
e pe
rf
orm
a
nce of t
h
e Ope
n
-
D
el
t
a
base
d
co
n
t
ro
ller is tested
fo
r all th
ese lo
ad
ing
co
nd
itio
n
s
to
es
tab
lish
its efficacy. Th
e syst
em is realized using the
m
o
d
e
ls in
Power
Syste
m
Bl
o
c
k-set av
ailable in
Matlab
Si
m
u
lin
k
(v
ersi
o
n
7
.
9) and
is
si
m
u
lated
in
discrete
m
ode at
0.
5
μ
s
ec step size
wit
h
ode
23tb (stiff/TR-BDF-2) s
o
lve
r
.
8.
SIM
U
LATI
O
N
RESULTS
AN
D DIS
C
US
SION
Th
e
fo
llo
wi
n
g
measu
r
em
en
ts were m
a
d
e
in
t
h
e m
o
d
e
l: th
e
v
o
ltag
e
acro
s
s
in
du
ctio
n
g
e
n
e
rato
r th
at is
also the voltage at th
e PCC
(Vabc), induction ge
nerat
o
r cu
rre
nt (iabc), load
current
(b
alan
ced
/
u
nb
alan
ced
/lin
ear/
n
o
n
-lin
ear) (ila, ilb
, ilc) o
r
(i
Lab
c
) , curren
t
throug
h
cap
acitor b
a
nk
ic-ab
c
, th
ree-
pha
se co
nt
r
o
l
l
e
r cu
rre
nt
s are
i
ca, i
c
b, i
cc, t
e
rm
i
n
al
AC
vol
t
a
ge at
t
h
e PC
C
(Vt
m
), i
ndu
ct
i
on ge
nerat
o
r
spee
d
(w
), DC bu
s v
o
ltage (V
dc
), ba
ttery
cur
r
ent (i
b)
.
8.
1
Perfor
mance
of System
under Linear L
o
ads
w
i
th
an
d w
i
thou
t
OD
-V
S
C
BESS
C
o
n
t
roller
The
per
f
o
rm
ance
of a
n
O
D
-
VSC
B
E
SS
b
a
sed c
o
nt
rol
l
e
r i
s
prese
n
t
e
d
i
n
Fi
gu
re
4.
At
0
.
3
sec
,
balance
d
three-pha
se linear loads a
r
e c
o
nnec
ted to t
h
e
PCC. Th
e
g
e
n
e
rat
o
r
su
pp
lies th
e load
sh
owing
i
n
crease
i
n
val
u
e o
f
i
a
b
c
. V
o
l
t
a
ge re
g
u
l
a
t
i
on as
pect
of t
h
e O
D
-
VS
C
B
E
SS ba
sed
cont
rol
l
e
r ca
n
be
obse
r
ved
fr
om
t
h
e
gene
rat
o
r t
e
rm
i
n
al
vol
t
a
ge
. A
t
0.4 sec o
n
e o
f
p
h
ases
of th
e lin
ear in
du
ctiv
e d
e
lta con
n
e
cted
lo
ad
is open
e
d
and at
0.
6 sec
anot
her l
o
a
d
p
h
ase i
s
al
so o
p
e
ned
,
m
a
ki
ng t
h
e l
o
ad c
o
m
p
l
e
t
e
l
y
unbal
a
nc
ed. At
0
.
5
5
sec
o
n
d
t
h
e
cont
rol
l
e
r i
s
di
sco
nnect
e
d
f
r
o
m
t
h
e ge
nerat
o
r an
d
n
o
w i
t
ha
s t
o
r
u
n
on i
t
s
exci
t
a
t
i
on
pr
o
v
i
ded
by
t
h
e ca
p
aci
t
o
r
ban
k
. T
h
e
vol
t
a
ge re
gul
at
i
o
n
pr
o
p
ert
y
of t
h
e
cont
r
o
l
l
e
r i
s
no
m
o
re in
fun
c
tio
n
as su
ch
the g
e
n
e
rator vo
ltag
e
d
r
op
s as it is
un
ab
le t
o
su
stain
with
ou
t th
e reactiv
e po
wer
su
pp
ly fro
m
th
e redu
ced
switch
DSTATCOM, it
fi
nal
l
y
fai
l
s
an
d dec
r
eases
fu
rt
her
.
At
0.
55
sec t
h
e co
nt
ro
ller cu
rren
t rises as it h
a
s to
n
o
w su
pp
ly the lo
ad
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Ope
n
-Del
t
a
VS
C
Base
d V
o
l
t
a
ge C
ont
r
o
l
l
e
r i
n
Isol
at
ed
Pow
e
r Syst
e
m
s
(Sh
ilp
i Bha
tta
ch
arya
)
38
2
cur
r
ents
due t
o
failure o
f
the
cont
roller.
It is furt
he
r
reconnected to the ge
nerat
o
r term
inals at 0.65 sec and
v
o
ltag
e
is ag
ai
n
regu
lated
at
its p
r
ev
iou
s
v
a
lu
e. Th
e
v
a
b
c
c, th
e co
n
t
ro
ller v
o
ltag
e
is always co
n
t
ro
lled
at th
e
d
e
sired
lev
e
l an
d
it sup
p
lies th
e lo
ad
du
ring th
e failu
re of
th
e in
du
ction
g
e
n
e
rator. Th
is estab
lish
e
s the lo
ad
lev
e
lin
g
feature of th
e OD-VSC con
t
ro
ller i
n
th
is iso
l
ated
n
e
two
r
k
.
8.
2
Perfor
mance
of O
D
-VS
C
B
E
SS Con
t
r
o
ller under
Linear Loads
Th
e syste
m
is
started
with
b
a
lan
ced three-phase star conne
cted indu
ctive loads as shown in Figure
5.
At
0.
3 sec one
of t
h
e p
h
ases
i
s
di
scon
nect
e
d
an
d at
0.4 se
c anot
he
r p
h
as
e i
s
di
scon
nect
ed. Th
e t
h
ree
-
pha
se
SEIG term
in
al vo
ltag
e
v
a
b
c
is regu
lated n
e
arly at its
rat
e
d set
val
u
e
an
d
gene
rat
o
r c
u
rre
nt
s rem
a
i
n
nearl
y
sin
u
s
o
i
d
a
l
du
ri
n
g
b
e
co
m
e
h
i
gh
ly un
b
a
lan
c
ed
lo
ad
i
n
g.
The ch
an
ge in load
ing
con
d
ition
s
is tak
e
n
care of
b
y
th
e con
t
ro
ller,
as can
b
e
seen
fro
m
th
e n
a
tu
re o
f
con
t
ro
ller cu
rren
ts, ch
ang
e
in
b
a
ttery cu
rren
t an
d th
e
ripp
les
in
th
e
DC
bu
s
v
o
ltag
e
during
th
e ti
m
e
in
terval 0
.
3
sec to
0
.
5
sec.
Fi
gu
re 4.
Per
f
o
rm
ance
of O
D
-
V
SC
B
E
S
S
ba
sed v
o
l
t
a
ge
c
o
nt
r
o
l
l
e
r
The
ge
nerat
o
r
cur
r
ent
s
rem
a
in c
onst
a
nt
s
h
o
w
n
by
i
a
bc
.
All loads a
r
e re
connected at 0.5 sec
.
T
h
e terminal
vol
t
a
ge
m
a
gni
t
ude
V
tm
is close to its
refe
re
nce
value
.
T
h
e load is s
w
itched off at
0.8 sec
and t
h
e
BESS
charges
up as
s
h
own
by battery current i
b
,
from
the excess
powe
r a
v
ailable from
the ge
nerator.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
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:
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94
I
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PED
S
Vo
l. 6,
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.
2,
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ne 20
15
:
376
–
3
86
3
83
Fi
gu
re 5.
Per
f
o
rm
ance
of O
D
-
V
SC
base
d DS
TA
TC
OM wit
h
linea
r loa
d
s
(balance
d/unbalanced)
Fi
gu
re 6.
Per
f
o
rm
ance
of O
D
-
V
SC
base
d DS
TATC
OM
wit
h
non-linear l
o
ads
(bala
n
ced/
u
nbalance
d)
8.
3
Perfor
mance
of System
under Non-Linear
Loads
Th
e
p
r
o
f
icien
c
y o
f
th
e
Op
en-Delta b
a
sed
DSTATC
OM is
n
o
w tested
with
b
a
lan
c
ed
/un
b
alan
ced
no
n-
linear loads and the res
u
lts are prese
n
ted in
Figure 6.
Thre
e single-phase diode rectif
ier
circuits are connected
with res
p
ect to the source ne
utral as
t
h
ree-
p
h
ase
no
n-l
i
nea
r
l
o
a
d
s. Eac
h
s
i
ngl
e
phase
rec
t
i
f
i
e
r su
ppl
i
e
s
5
k
W
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Ope
n
-Del
t
a
VS
C
Base
d V
o
l
t
a
ge C
ont
r
o
l
l
e
r i
n
Isol
at
ed
Pow
e
r Syst
e
m
s
(Sh
ilp
i Bha
tta
ch
arya
)
38
4
resistive loa
d
a
t
the
DC side
a
n
d ha
s filter c
a
p
acitor
connec
ted across each rectifie
r
l
o
a
d
. The non-linaer
loa
d
currents a
r
e s
h
own as iLa, iL
b and iLc. T
h
e
cont
roller c
u
rrents ica, icb a
n
d icc are
highly non-linea
r s
o
as to
com
p
ensate for the i
n
jecte
d
harm
onics
b
y
the n
on-
lin
ear
l
o
ad
s.
A
t
0.4 sec o
n
e
of
th
e
ph
ases of
th
e
no
n-lin
ear
lo
ad is
o
p
e
n
e
d
,
wh
ereas at
0
.
6 sec t
h
e
o
t
h
e
r
ph
ase is
also open
e
d.
Du
ring th
ese
un
b
a
lan
c
ed
con
d
ition
s
t
h
e lin
e
cur
r
ent
s
at
t
h
e generat
o
r si
de
sho
w
m
i
nor i
m
bal
a
nces
due
to the fact th
at one of the three
-
phase ge
nerat
o
r
terminals is connected to the capac
ito
r m
i
d
-
po
in
t at th
e DC bu
s, bu
t
th
e g
e
n
e
rat
o
r cu
rren
ts are
m
o
stl
y
si
nus
oi
dal
wa
v
e
fo
rm
s. From
0.
4 sec t
o
0.
6 sec t
h
e DC
bu
s ri
ppl
es i
n
c
r
e
a
ses and i
n
di
c
a
t
e
s how t
h
e
O
D
-
V
SC
co
n
t
ro
ller supp
lies th
e
h
a
rmo
n
i
c curren
t
s i
n
tro
d
u
c
ed
in th
e system
d
u
e
to
n
on-lin
eari
t
y o
f
t
h
e load. Th
e
gene
rat
o
r
v
o
l
t
a
ge
rem
a
i
n
s al
m
o
st
st
eady
at
t
h
e
refe
rence
m
a
gni
t
ude
Vt
m
under
al
l
su
ch t
h
e
a
b
o
v
e l
o
adi
n
g
co
nd
itio
ns. At
0
.
8
s
ec all th
e n
o
n
-
linear l
o
ads are
d
i
scon
n
ected
and
t
h
e av
ailab
l
e ex
cess
p
o
wer
go
es in
char
gi
n
g
t
h
e
b
a
t
t
e
ry
at
t
h
e D
C
b
u
s s
h
o
w
n
b
y
bat
t
e
ry
cu
rre
nt
an
d
DC
b
u
s
vol
t
a
ge
ri
se t
o
i
t
s
refere
nce
va
l
u
e.
9.
PER
F
ORM
A
N
C
E
C
O
M
P
A
R
I
SON
OF PR
OPOSE
D
CON
T
R
O
LLER
WIT
H
STAND
ARD
CONTROLLER
A c
o
m
p
ari
s
on
of
pe
rf
o
r
m
a
nce res
u
l
t
s
o
f
t
h
e
pr
opo
sed
r
e
du
ced
sw
itch
co
n
t
ro
ller
an
d ex
isting
st
anda
rd t
o
p
o
l
ogy
based c
o
nt
rol
l
e
r i
s
i
n
di
cat
ed i
n
Ta
bl
e 1.
The res
u
l
t
s
i
n
Tabl
e 1 i
n
di
cat
e t
h
at
t
h
e % T
HD
of
th
e g
e
nerator
v
o
ltag
e
s and
cu
rren
ts
u
n
d
e
r
d
i
fferen
t
lo
ad
i
n
g
co
nd
ition
s
are well with
in
th
e IEEE stan
d
a
rd
s.
A
lth
oug
h co
mp
ar
ed
t
o
a stan
d
a
rd
topo
logy b
a
sed
D
S
TA
TCO
M
th
e
% THD’
s ar
e
slig
h
tly h
i
gh
er bu
t the
ad
v
a
n
t
ag
e lies
in
th
e
fact th
at
it is ob
tain
ed
b
y
redu
c
tio
n in
IGBT’s i
n
the con
v
e
rter circu
itry wh
ich bring
s
ab
ou
t a
red
u
c
ti
o
n
in
ov
erall syste
m
co
st.
Tabl
e
1. C
o
m
p
ari
s
o
n
of
% T
H
D
f
o
r
PC
C
v
o
l
t
a
ge a
n
d
s
o
u
r
ce cu
rre
nt
f
o
r
a
DST
A
TC
OM
base
d
on
re
duc
ed
sw
itch
t
o
po
logy an
d a stan
d
a
rd
inv
e
r
t
er
topolo
g
y
T
y
pe of L
o
ad
% THD
of L
o
ad
Cu
rren
t
s
% THD
for Open-Delta Controller
(
4
–switch)
% THD
f
o
r Stan
d
a
rd
Co
n
t
ro
ller
(6
-switch
)
Gener
a
tor
Voltage
Sour
ce
cur
r
e
nt
Gener
a
tor
Voltage
Sour
ce
cur
r
e
nt
L
i
near
Balanced Load
2.
5
1.
88
2.
98
0.
25
0.
66
L
i
near
Unbalanced
L
o
ad
3.
8
1.
7
4.
37
0.
31
1.
04
Non-
L
i
near
Balanced L
o
ad
31
4.
08
2.
21
1.
41
2.
64
Non-
L
i
near
Unbalanced
L
o
ad
68.
11
4.
78
2.
3 1.
57
2.
67
Sys
t
em P
a
r
a
meters
(I
)
15
k
W
, 4
1
5
V
,
50
Hz, Y
-
c
o
n
n
ect
ed
4-
pol
e
As
ync
h
ronous machine:-
Stator resistance, R
s=
0
.
435
Ω
,
roto
r
resistance, R
r
′
=0.816
Ω
,
Sta
t
or reactance X
s=
1.
5
Ω
,
rot
o
r reactance
, X
r
′
=2
Ω
, M
u
t
u
al Inducta
n
ce
,
L
m=
0.13
4
H,
M
o
m
e
nt
of
Ine
r
t
i
a
, J=
0.
13
8
4
Kg
-m
2
(II)
OD-VSC BESS Con
t
ro
ller
Para
m
e
ters:-IGBT b
a
sed
2-arm b
r
idg
e
config
uration
,
sp
lit cap
acito
r
3
rd
arm
o
f
3-ph
ase conv
erter:
- Sp
lit Cap
acito
rs:
C
1=
C
2
=2
20
0 µF, IG
BT sw
itch
i
ng
f
r
e
q
u
e
n
c
y=20
k
H
z, R
f
=0.004
Ω
, L
f
=7
m
H
, R
C
Filter: 1
Ω
i
n
ser
i
es
w
ith
20
0
μ
F, PI Con
t
ro
ller Gai
n
:
K
pa=
0.
0
5
, K
ia
= 0.
02
, K
pb
= 0.05,
K
ib
= 2, Battery
Vo
ltag
e
,
V
B
=
1
50
0 V;
R
s
=0.1
Ω
; R
B
=10 K
Ω
; C
B
=2
500
0
Ω
(III)
Prim
e
Mover Characteristics
:
T
sh
=K
1
- K
2
ω
r
, K
1=
3
100
, K
2=
2
(I
V)
Li
near:
3 k
W
, 20
0 V
A
R
per
pha
se
(
u
nbal
a
n
ced
l
o
ad
)
a
n
d
3 k
W
, 2
0
0
V
A
R
c
onst
a
nt
l
o
ad;
N
o
n
-
l
i
n
ea
r:
Th
ree
sing
le ph
ase b
r
i
d
g
e
rectifier
with
5kW resi
stiv
e lo
ad
s
o
n
DC
sid
e
with
filter cap
acitan
ce 200
μ
F
10
.
CO
NCL
USI
O
N
The co
nt
r
o
l
,
s
i
m
u
l
a
t
i
on and
per
f
o
r
m
a
nce of an O
D
-
V
SC
B
E
SS cont
r
o
l
l
er ope
rat
e
d t
o
abso
rb
or
inject reacti
v
e
powe
r supply in an is
olated
powe
r system
fed from
isolated
induction ge
nerator is presented in
t
h
i
s
pape
r. Th
e resul
t
s
obt
ai
ned ar
e qui
t
e
sat
i
s
fact
ory
.
The O
D
-
V
SC
funct
i
ons
pr
o
p
erl
y
an
d reg
u
l
a
t
e
s
gene
rat
o
r
v
o
l
t
a
ge
ho
we
ver
se
vere
t
h
e
l
o
a
d
t
y
pe m
a
y
be. A
n
y
p
o
w
er
sy
st
em
i
s
su
bject
e
d
t
o
l
i
n
ea
r a
n
d
n
o
n
-
linear loads
,
single
-
phase loa
d
s cause se
ver
e
un
bal
a
nce
d
cur
r
ent
s
i
n
t
h
e s
y
st
em
, but
i
t
has been o
b
se
rv
ed t
h
a
t
th
e v
o
ltag
e
s at th
e PCC re
main
s n
early
sinusoi
d
al and at its refere
nce va
lue, the curre
nt wave
form
s
at the
g
e
n
e
rator lin
es also
retain
th
eir set v
a
lu
es an
d
are also
cl
osely sinusoi
dal
in nature eve
n
whe
n
the loa
d
s are
lin
ear or
n
on-lin
ear typ
e
un
der b
a
lan
ced or u
n
b
a
la
n
ced
co
nd
itio
ns. Th
e co
n
t
ro
ller
u
s
es lesser
n
u
m
b
e
r
of
act
i
v
e devi
ces
,
t
hus a g
o
od a
m
ount
of re
d
u
c
t
i
on i
n
c
o
st
i
n
t
e
rm
s of IG
B
T
’s can
be a
c
hi
eve
d
wi
t
h
pr
o
p
er
d
e
sign
ing
of su
ch
a con
t
ro
ller. IGBT’s co
un
t is lesse
r add
i
ng t
o
savi
ng
s of t
h
e sy
st
em
.
Thi
s
red
u
ce
d s
w
i
t
c
h
DST
A
TC
OM
i
s
al
so ca
pa
bl
e
of
p
r
o
v
i
d
i
n
g
h
a
rm
oni
c red
u
ct
i
on a
n
d l
o
a
d
l
e
vel
i
n
g
.
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
.
2,
Ju
ne 20
15
:
376
–
3
86
3
85
REFERE
NC
ES
[1]
B. Singh, S.S. Murty
and S.S.
Gu
pta, “Statcom based voltage regu
lator
for Self-Ex
c
ited induction generator feed
ing
non-linear lo
ads
”
,
I
E
EE Trans. I
nd. Electron
, Oct. 2006
, vo
l. 53,
no. 5
,
pp
. 1437–
1452.
[2]
G.K. Singh, “Self-excite
d
induction gener
a
tor research – a survey
”,
E
l
ec
tr
ic Po
wer
Sys
t
em Res
e
ar
ch
, May
200
4,
vol. 69
, no
. 2-3
,
pp. 107-114
.
[3]
R.C. Bansal, “Three Phase
self
excited inductio
n generator
:
an
overview”,
IEEE Trans. on En
ergy Conversion
,
June 2005vol.20
,
no
.2, pp. 292-2
99.
[4]
R.C. Bansal
, T.S. Bhatti and
D.P. Ko
thari, “Bibliograph
y
on
the appli
cat
ion
of Induction Generator in Non-
Conventional en
erg
y
s
y
s
t
ems”,
I
EEE Trans. on Energy Conversion
,” Sep
t
. 2003, v
o
l.
EC-18, no.3
,
pp. 433-
439.
[5]
D.B. Watson and I.P. Milner
, “Aut
onomou
s and Parallel
operation of se
lf excited indu
ction gen
e
rator
”
,
International Jo
urnal of
Elec
trical Eng
i
neering
Education
,
1985
, vol.22, pp.365-
374.
[6]
A.
H.
Al-Bahrani and N.
H.
Malik,
“
Steady Sta
t
e Analysis of par
allel op
erated s
e
lf-
excited
induction gen
e
rator
”,
IEE Proceed
ings
,
1993
, vol. 140
,
no.1, pp. 49-55.
[7]
B. Singh, S.S.
Murth
y
, and S.
Gupta,
“Analy
sis and design of
STATCOM based voltage r
e
gul
ator for self-ex
c
ited
Induction
gen
e
rator”,
IEEE Trans. En
ergy Con
ver
s
. Dec 2004, vol. 19,
no. 4, pp. 78
3–790.
[8]
B.N. Singh, B.
Singh, A. Chan
dra and
K.A. H
a
ddad, “Digital imp
lementation
of an advan
ced static compensator
for voltag
e
profile improvement, power factor co
rrection
and b
a
lancing of unbalan
ced reactive
load
s Power Sy
stem
Research
54, 20
00, pp
. 101-111
.
[9]
Am
barnath Banerjee, Sujit K
Biswas and
Bhim
Si
ngh, “DSTATCOM
Control Algorit
hm
s: A Review”,
International Jo
urnal of Power
Elec
tronics and
Drive System (
I
JPEDS)
,
September 2012, Vol. 2
,
No. 3, pp. 285
-
296.
[10]
R.C. Dugan
,
M
.
F
.
M
c
Granaghan
,
S
.
S
a
ntos
o and
H. W
.
Bea
t
y, “
E
le
ctri
cal
P
o
wer S
y
s
t
em
s
Qualit
y”
,
Tata M
c
Graw
Hill Educat
io,
2
010,
New Delh
i, 2nd
. Ed
. 2010
.
[11]
T. Larsson,
C
.
Poumarede,
“
STATCOM, an e
f
f
i
ci
ent means
fo
r flic
ker mi
tigat
ion
”,
IEE
E
P
o
wer Engin
eerin
g
Society
1999 Winter Meeting
,
Feb. 1999
, vol. 2
,
p
p
. 1208-1213
.
[12]
C. Schauder
,
“S
TATCOM for compensation of l
a
rge ele
c
tric ar
c furnace
install
a
tions
”, I
EEE Power Engineerin
g
S
o
ciet
y S
u
m
m
e
r M
eet
ing
July
,
1
999, vol .2
pp. 1
109-1112.
[13]
B. Blazic, I
.
Pap
i
c, “
Ana
l
ysis of f
lic
ker mitiga
tion
in
a uti
lit
y distr
i
bution n
e
twork
”, IEEE Reg
i
on 8
Computer as a
tool
EUROCON 2003, Sept.
200
3, vol. 2
pp. 292
-296.
[14]
Z. Zhang
,
N.R.
F
a
hm
i, W
.
T. Norris, “
Flick
e
r Analysis and Methods for El
ectri
c Arc Furnace Fl
ick
e
r (
EAF)
Mitigat
ion (
A
Su
r
vey)
”, I
E
EE Por
t
o Power Tech
.
Conference, Sep
t
2001
pp
. 1-6
.
[15]
J. Sun, D. Czarkowski and
Z. Zabar
,
2002
, “
Voltag
e
Flicker Mitigation
Using PWM-Ba
s
ed Distributio
n
STATCOM
”, IEEE Power
Engg. Society
Summer Meet. Vol. 1
p
p
. 616-621
.
[16]
A. Ghosh and
A. Joshi, “A ne
w approach to load bala
n
c
ing and power factor
correction in p
o
wer distributio
n
s
y
s
t
em
”,
IEEE T
r
ans. on Pow
e
r
Delivery
, 2000,
vol.15,no
. 1
,
pp
.
417-422.
[17]
Am
barnath Ban
e
rjee, Suji
t K Bi
swas and Bhim
Singh,
“DSTATCOM Applicati
on for Mitigat
io
n of Voltage Sag
Caused b
y
D
y
n
a
mic Loads in Au
tonomous
Power Sy
stems”,
International Journal of Power Electr
onics and Drive
Sys
t
em (
I
JPEDS
)
,
June 2012, Vol.2, No.2
, pp
. 23
2-240.
[18]
B. El Badsi, B.
Bouzidi, A. Mas
m
oudi, “DTC Scheme for
a Four-Switch I
nver
t
er-Fed Induction
Motor Emulatin
g
the Six-Switch I
nverter
Operatio
n”
, I
E
EE Transactions Power
Electroni
cs, 2013
,
Vol.:28, Issue:7, pp 3528-3538
.
[19]
V.
Krishnaveni,
K.
Kiruthika, S.S Kuma
r, “Design and
implementation
of
low
cost four switch
inverter
for B
L
DC
motor drive with
active power
factor
co
rrection
”
,
Proc. ICGCCEE, 2014
, pp
1-7.
[20]
R. Akhila, M.P.
Varghese, V.S.
Anooja,
S. Nikhil, “Torque ripp
le reduction of four-switc
h inverter fed permanen
t
magnet brushless DC
motor using h
y
ster
esis co
ntroller”
, Conf
.
Proc. Power Signals Control an
d Computations
(EPSCICON), 2014, pp
. 1-6
[21]
R. Akhila
, S
.
Ni
khil, “
A
com
p
ar
ativ
e com
p
ara
tiv
e s
t
ud
y of
senso
r
and sensor less cont
rol of
four
-switch Inver
t
er
fed Permanent
Magnet Brushles
s DC
motor”, Proc. Power,
Signals, Controls and
Co
mputation (EPSCICON), 2012,
p.p 1-6
.
[22]
H.
W.
Van Der
Broeck and J.
D.
van W
y
k, “
A
com
p
arative inv
e
stigation
of a thr
ee-phas
e
indu
cti
on m
achine drive
with a
component minimized v
o
ltag
e
-fed
i
nverter under d
i
ffer
e
nt contro
l optio
ns”,
IEEE Trans. Ind. App
l
icat
.,
1984
,
vol. IA-20
,
no
. 2
,
pp
. 309–
320.
[23]
H.W. Van Der
Broeck and H.C. Skude
ln
y
,
“Analy
tical an
aly
s
is of the
harmonic effects of
a PWM ac drive”,
IEEE
Trans. Pwr. Elec
., Apr.,1988
, vo
l. PE-3
, no
. 2
,
pp
.216-223.
[24]
G.T. Kim and T.A Lipo
, “VSI
-P
WM rectifier/inverter s
y
stem
with a reduced switch count
”
,
I
EEE T
r
ans. Ind.
Appl.
, Nov/Dec
1996, vol.23,
no. 6, pp. 1331-133
7.
[25]
Y.K. Lo, T.H
.
Song and H.J. Ch
iu, “A
nal
y
s
i
s an
d elim
ination of
voltag
e
im
bal
a
n
ce between
the s
p
lit
capaci
t
ors in
half-bridg
e boos
t rectif
iers”,
I
E
EE Trans. on Ind
.
Electronics
, Oct. 2002, Vol. 49,
No. 5, pp 1175-1
177.
[26]
M.B.R. Correa,
C.B. Jacob
i
na, E.R.C
.
Da Silva and A.
M.
N.
Lima,
“A Ge
neral PWM Strateg
y
for Four-Switch
Three-P
h
as
e
Inv
e
rters
”
,
I
E
EE Trans. on
Power Electronics
, Nov.
2006, Vol. 21
, N
o
. 6
,
pp
1618-16
27.
[27]
G.I. Peters, G.A
.
C
ovic and J
.
T. Bo
y
s
, “
Elimina
ting outpu
t distortion in f
our-S
witch
inverters with three-phas
e
loads
”, I
E
E Proc. Electr. Power
Appl. 1998
, Vol. IA-34, pp
. 326-
332.
[28]
C.B. Jacobina, E.R.C. Da
Silva and A.
M.
N.
Lima,
and R
.
L.A. Rib
e
iro. “
Vector an
d Scalar control of a four switch
three phase in
verter
”, In
Conf
. R
ec. IAS, 1995
, p
a
ges 2422-2429
.
[29]
F.
Blaa
bje
r
g,
S.
Frey
sson,
H.
H.
Hansen and S.
Hansen, “
A new
optimized space vector
modula
tion strateg
y
for
a
component min
i
mized voltage source in
verter
”, in Proc. IEEE AP
EC’95, 1995
, vo
l. 2
,
pp
. 577–585
.
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