Internati
o
nal Journal
of App
lied Power E
n
gineering
(IJAPE)
V
o
l.
3, N
o
. 1
,
A
p
r
il
201
4, p
p
.
15
~22
I
S
SN
: 225
2-8
7
9
2
15
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
/
IJAPE
Combined Op
eration of SVC, PS
S and Increasing Inertia of
Machine for Power System Tr
ansient Stability Enhancement
B
a
bl
esh Kum
a
r Jh
a, R
a
mje
e
Pras
ad
Gu
p
t
a
,
U
p
endr
a P
r
as
ad
Ele
c
tri
cal
Engg
.
D
e
pt.,
B.I
.
T
S
i
n
d
ri
Article Info
A
B
STRAC
T
Article histo
r
y:
Received Dec 5, 2013
Rev
i
sed
Jan 28, 201
4
Accepte
d
Fe
b 7, 2014
In this pa
pe
r improve
me
nt of tra
n
sie
n
t sta
b
ility
by
c
oordination of PSS
(P
ower S
y
s
t
em
S
t
abili
zer) and S
V
C (S
tatic var C
o
m
p
ens
a
tor) and increas
ing
inertia of s
y
nchr
onous machine
has been
observ
e
d. Because sing
le method is
not sufficient for
im
proving stabilit
y. For this purpose a 9 bus m
u
lti m
achine
s
y
s
t
em
has
be
en
cons
ider
ed.
Tra
n
s
i
ent s
t
ab
ili
t
y
i
m
p
rovem
e
nt has
been
tes
t
e
d
subjected to
thr
ee ph
ase f
a
ult at bus
3
after 0
.
5
second
and f
a
u
lt h
a
s been
cleared af
ter 1 second. B
y
the
use of
PSS, SVC and b
y
incr
easing inertia
method for th
e
test s
y
s
t
em th
e
electr
omech
anical os
cillation
fo
r gener
a
to
r
ele
c
tri
cal
power
has
been
redu
c
e
d and
the s
t
ea
d
y
s
t
ate
power
trans
f
er h
a
s
been enhan
ced
.
In this paper t
h
e Inerti
a of th
e m
achine is n
o
t so m
u
c
h
incre
a
sed. Be
ca
use after in
crea
sing inerti
a of the m
achine ro
t
o
r will be
havier
.so that
it
is kept alwa
ys
within
lim
it as c
onsidering its re
liabi
lit
y
and
econom
y
.
And f
i
eld vo
ltag
e
is als
o
kept limited.
Keyword:
Transien
t stab
ility
PSS
Ex
icter
SVC
Copyright ©
201
4 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
:
U
p
end
r
a P
r
as
ad
,
Ele
c
tri
cal
Engg
.
D
e
pt.,
B.I
.
T
S
i
n
d
ri
.
Em
a
il: Up
end
r
a_
b
it@yah
o
o
.
co
.in
NO
MEN
C
LA
TURE
Para
m
e
ter Defintion
Para
m
e
ter Definition
Ra
ar
m
a
tu
re
resistan
c
e
in
o
h
m
Xd”, Xq”
dir
ect-
a
xis,
quadr
atur
e-
axis sy
nchr
onous subtr
a
nsient
reactance
in perce
n
t
Xd’,Xq’
dir
ect-
a
xis,
quadr
atur
e-
axis sy
nchr
onous
transient
reactance
in perce
n
t
Xd,Xq
direct-axis,quadrat
ure-axis
sy
nchronous reactance in
percent
X1
positive sequence reactance
R0,X0
zero sequence resi
stance.react
ance
X/R
arm
a
ture X/R
ratio
Td0” ,Tq”
dir
ect-
a
xis,
quadr
atur
e-
axis subtr
a
nsient open cir
c
uit tim
e
constant in second
s
T
d0’
,
T
q’
dir
ect-
a
xis,
quqdr
atur
e-
axis tr
ansient o
p
en-
cir
c
uit ti
m
e
constant in seconds
H
inter
tia of sy
nchr
onous
m
achine
D
shaft
m
e
chanical d
a
m
p
ing ter
m
in percent
S100,
S120
satur
a
tion factor
at 100%,
120% term
inal voltage
Sbreak
per unit of term
ina
l
voltage at which t
h
e
generator saturatio
n curve skews f
r
om
the ai
r-
gap line.
VSI
PSS input (speed,
power or frequency
)
in pu
KS
PSS gain(p.u)
VST
m
ax,
VST
m
in
Maxi
m
u
m
,
Mini
mu
m
PSS output(p.u)
T
D
R
Reset tim
e
delay
for
discontinuo
us
co
n
t
ro
ller(sec.
)
A1,A2
PSS signal conditioning
freque
ncy
filter constant(p.u)
T1
,T3
PSS lead co
m
p
ensation ti
m
e
constant
(sec.)
T2,T4
PSS leg co
m
p
ensat
i
on ti
m
e
constant(s
ec.)
T5,T6
PSS washout ti
m
e
constant(sec
KA
Regulator
gain(
p
.
u
)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
252
-87
92
IJA
P
E Vol
.
3
,
No
. 1, A
p
ri
l
20
14
:
15
–
2
2
16
Ef
d
m
ax
M
a
xim
u
m
exciter
output v
o
ltage(
p
.
u
)
KE
E
x
c
iter
constant for
self-
e
xcited field(p.
u)
Kf
Regulator stabilizing circuit gain(p.u)
TA
Regulator
am
plifier
ti
m
e
constant(
s
ec.
)
TB,TC
Voltage r
e
gulator
tim
e constant(
s
ec.
)
T
E
Exciter ti
m
e
constant(sec.)
TF,
Regulator stabilizing circuit,Input filter ti
m
e
constant(
s
ec.
)
T
R
Regulator
I
nput fil
t
er
ti
m
e
constant(
s
ec.
)
VR
m
a
x,
M
a
xim
u
m
value of the r
e
gulator
output
voltage(
p
.
u
)
VR
m
i
n
M
i
nim
u
m
v
a
lue of the r
e
gulator
output voltage(
p
.
u
)
SEm
a
x
T
h
e value of excitation functio
n at Efd
m
ax
SE
.
75
T
h
e value of excitation functio
n at 0.
75 E
f
d
m
ax
K Voltage
r
e
gulator
gain(
p
.
u
)
a1,
a
2
Additional contr
o
l signal gain
T
Voltage r
e
gulator
tim
e constant(
s
ec.
)
t
m
Measure
m
ent ti
m
e
constant(sec.)
T
b
T
h
y
r
istor phase contr
o
l tim
e
constant(
s
ec.) td
Thyristor
phase
contr
o
l delay
(
sec.
)
t1,
t
2
Voltage r
e
gulator
tim
e constant(
s
ec.
)
tb
m
a
x
,
t
b
mi
n
M
a
x
i
mu
m,
mi
n
i
mu
m
s
u
s
c
e
p
t
a
n
c
e
l
i
mi
t
(
p
.
u
)
1.
INTRODUCTION
Electrical power system
s are
being
m
o
re a
n
d m
o
re c
o
m
p
licated e
v
er
y year
an
d pro
p
o
r
ti
o
n
a
lly th
eir
analysis will also
becom
e
m
o
re difficult. S
o
,
there is
a
n
inte
nse
need to
use
m
o
re efficient
m
e
thods
for powe
r
syste
m
an
alysi
s
. On
e
o
f
th
e
m
o
st i
m
p
o
r
tan
t
to
p
i
cs i
n
p
o
wer system
is th
e in
sp
ecti
o
n
of th
e tran
sien
t stab
ility
wh
en
po
wer
syste
m
b
e
in
g su
bj
ected to a
co
n
ting
e
n
c
y.
Tran
sien
t stab
ili
ty is th
e ab
ility o
f
power sy
ste
m
t
o
keep its synchronism
when a large di
sturba
nce, like three
pha
se short circ
u
it, o
ccurs in
th
e syste
m
. Se
v
e
ral
facto
r
s lik
e t
h
e in
itial co
nd
i
tio
n
o
f
th
e
power
system
,
t
y
p
e
, sev
e
rity
an
d lo
cation
of th
e
fau
lt affect th
e
transient sta
b
ility. The m
a
xim
u
m
dura
tion that one fa
ult can rem
a
in in
the power sy
stem
without
causing
in
stab
ility is th
e critical cleari
n
g
tim
e (CCT) o
f
th
at
fa
u
lt. Im
p
r
o
v
e
m
e
n
t
s i
n
transien
t stabilit
y p
e
rfo
r
m
a
n
ce
of
p
o
w
e
r syste
m
s h
a
v
e
b
een
ach
i
ev
ed
trad
itio
n
a
lly th
ro
ugh u
s
es of h
i
gh-sp
eed
fau
lt-cl
earing
,
h
i
g
h
i
n
itial-
respon
se ex
cit
e
rs, series cap
acito
rs, facts co
n
t
ro
ller an
d
o
t
h
e
r stabilit
y
m
easu
r
es [1
]-[3
].
W
i
t
h
th
e
d
e
v
e
l
o
p
m
en
t of m
o
d
e
rn
po
wer system
s, th
ere is a tend
en
cy
of in
creased
co
m
p
lex
ity o
f
st
ab
ility p
r
ob
lem
s
an
d
an inc
r
easing
conce
r
n about conseque
nces of
i
n
stability.
The need for
i
n
troducing ne
w
m
e
t
hods to i
m
prove
stab
ility h
a
s b
een
wi
d
e
ly recog
n
i
zed
.
Th
e mo
d
e
l
d
e
v
e
l
o
p
e
d so
far fo
r transien
t stab
ility a
n
alysis h
a
s assu
m
e
d
bal
a
nce
d
t
h
ree
pha
se o
p
erat
i
o
n eve
n
d
u
ri
ng t
h
e fa
ul
t
peri
od [
2
]. A
ltho
ugh
th
r
ee-ph
as
e fa
ult are in m
o
st
cases
th
e m
o
st o
n
e
rou
s
, t
h
ere are o
c
casio
n
s
wh
en
un
symmetr
ical fau
lt con
d
ition
s
n
e
ed
to b
e
analyzed
[3
].
In
th
is
p
a
p
e
r im
p
r
o
v
e
m
e
n
t
o
f
tran
sien
t stabilit
y an
alysis o
f
9
-
bu
s m
u
lti
mach
in
e system b
y
u
s
in
g
th
e
co
ord
i
n
a
ted effect of
po
wer
syste
m
stab
iliz
er(PSS),static v
a
r co
m
p
en
sat
o
r(or
SVC
)
and
b
y
in
creasing
the
in
ertia of the
mach
in
e.
In th
i
s
analysis
we c
r
eate a three
phase
fault
on
sp
ecified bu
s and
th
en
i
n
v
e
stigatio
n
is
to analyse the
beha
viour of the sync
h
r
on
ous
m
ach
in
e. Fo
r th
is work
we
use
d
t
h
e l
i
cens
e
d pac
k
a
g
ed
of
ETA
P
soft
ware
.
The
pa
per i
s
o
r
gani
se
d as
f
o
l
l
o
ws:
sect
i
o
n
2
gi
ves a
b
r
i
e
f i
n
t
r
o
duct
i
o
n
of
p
o
we
r sy
st
em
stabi
l
i
zer (
o
r
PSS) a
nd static var com
p
ens
a
tor (or S
V
C).
A
9-bus m
u
lti
m
achine system
or test
sys
t
em
is described In
sect
i
on 3
.
Th
e com
put
er si
m
u
l
a
t
i
on res
u
l
t
s
f
o
r sy
st
em
und
er st
u
d
y
are p
r
esent
e
d a
nd
di
scusse
d i
n
Sec
t
i
on 4
and
i
n
Sect
i
o
n 5
c
oncl
u
si
o
n
s are gi
ve
n.
2.
MODEL SYSTEM
Th
e test system th
at h
a
s b
e
en
con
s
i
d
ered
here is th
e 9-Bus Mu
lti-Mach
in
e System
as s
h
own
b
e
l
o
w
i
n
Fi
g
.
(a
).
whi
c
h c
o
n
s
i
s
t
e
d
9-
bus
, t
h
ree
ge
n
e
rat
o
r
s
,
fo
u
r
c
a
bles,fi
v
e tra
n
sform
e
r an
d
t
w
o
lo
ad
s on
e is
static
l
o
ad
o
f
1
0
0
M
VA a
n
d a
n
ot
he
r i
s
a
n
i
n
duct
i
o
n m
o
t
o
r
of
2
5
M
W
.
Gen
-
1,G
e
n
-
2
and
Ge
n-
3
rat
e
d
of
8
5
M
W
,
1
2
7
.
5
M
W
a
n
d
17
0
M
W
res
p
ect
i
v
el
y
.
Al
l
ot
her
i
n
put
pa
ram
e
t
e
rs o
f
ge
nerat
o
rs
are
sho
w
n
be
l
o
w
i
n
Table-1,2 and
3. T
h
e I
EEE type of DC
1 e
x
citer, with c
o
ntinuously
acting
voltage re
gulators are installed with
all g
e
n
e
rato
rs. Th
e ex
citer
is self ex
icted,.Wh
e
n
self
-ex
c
ited
,
Ke is selected
so
t
h
at in
itially
Vr =0,
rep
r
ese
n
t
i
ng
o
p
erat
or act
i
o
n
of t
r
acki
n
g
t
h
e
vol
t
a
ge
re
gul
at
o
r
by
pe
r
i
odi
cal
l
y
t
r
im
m
i
ng t
h
e s
h
u
n
t
fi
el
d
rhe
o
st
at
set
po
i
n
t
.
I
n
put
dat
a
of e
x
i
c
t
e
r i
s
sh
ow
n i
n
Ta
bl
e-
4.
A
n
d
IEE
E
t
y
pe o
f
P
S
S
1
A
i
s
con
n
ect
e
d
w
i
t
h
al
l
gene
rat
o
rs.T
he
param
e
t
e
rs of pow
er sy
st
em
st
abi
l
i
zer i
s
sho
w
n i
n
Tabl
e
-
5
.
SVC
1 i
s
con
n
ect
ed i
n
s
h
u
n
t
at
th
e bu
s-
9 of
Gen
-
3
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
APE
I
S
SN
:
225
2-8
7
9
2
C
o
m
b
i
n
e
d
O
p
e
r
at
i
o
n of
SVC
,
PS
S an
d Inc
r
e
a
si
n
g
Ine
r
t
i
a
o
f
Mac
h
i
n
e
f
o
r Pow
e
r Syst
em
(
B
abl
es
h
K
u
m
a
r
J
h
a)
17
Tab
l
e-1
:
SY
NCH
R
ON
OU
S
MA
CH
IN
E PA
RA
METERS
Machine
Rating
Positive sequence im
p
e
dence(%) Zero
seq.
Z(%
)
ID
TYPE
MOD
E
L
MVA
KV
R
a
X
d
” X
d
’ X
d
X
q
” X
q
’ X
q
X
1
X/R R
0
X
0
Gen1 Gener
a
tor
Subtr
a
nsient,
Round-
Rot
o
r
100
11
1
19
28
155
19
65
155
15
7
1
7
Gen2 Gener
a
tor
Subtr
a
nsient,
Round-
Rot
o
r
150
13.
2
1
19
28
155
19
65
155
15
7
1
7
Gen3 Gener
a
tor
Subtr
a
nsient,
Round-
Rot
o
r
200
11
1
19
28
155
19
65
155
15
7
1
7
Table-2: DYNAMIC PAR
A
METERS
OF
SYNCHR
ONOUS MAC
H
INE
M
achine
Connected bus
T
i
m
e
cons.
(
sec.)
H(
Sec.
)
,
,
D
(MW
p
u
/Hz)
&
S
atur
ation
Gr
ounding
ID
ID
T
d0
” T
d0
’ T
q0
” T
q0
’
H
%D
S100
S120
Sbr
eak
Conn.
T
y
pe
Gen1
Bus1
0.
03
6.
5
0.
03
1.
25
12
0
1.
7
1.
18
0.
8
W
Y
E
SOL
I
D
Gen2
Bus4
0.
03
6.
5
0.
03
1.
25
12
0
1.
7
1.
18
0.
8
W
Y
E
SOL
I
D
Gen3
Bus9
0.
03
6.
5
0.
03
1.
25
12
0
1.
7
1.
18
0.
8
W
Y
E
SOL
I
D
Table-3: MEC
H
ANIC
AL
PARAM
ETERS OF SYNCHR
ONOUS
M
A
C
H
INE
M
achine
Gener
a
tor
/
M
o
tor
Couplin
g
Pr
im
e M
over
/
L
o
ad
E
quivalent T
o
tal
ID
TYPE
WR
2
RPM H
W
R
2
RPM H
W
R
2
RPM H
W
R
2
RPM H
Gen1
Gen.
3240
6
1500
4
3240
6
1500
4
3240
6
1500
4
9721
7.
99
1500
12
Gen2
Gen.
4860
9
1500
4
4860
9
1500
4
4860
9
1500
4
1458
26.
98
1500
12
Gen3
Gen.
6481
1
1500
4
6481
1
1500
4
6481
1
1500
4
1944
32.
98
1500
12
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.
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,
No
. 1, A
p
ri
l
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14
:
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–
2
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18
Table-4: E
X
CITER INP
U
T
DATA
T
y
pe: DC1
Machine
ID
Contr
o
l
Bus ID
KA
Ef
d
ma
x
KE
KF
TA
TB
TC
TE
TF
TR VR
ma
x
VR
mi
n
SE
ma
x
SE
.
75
Gen1 Bus1
46
2.
63
0.
05
0.
1
0.
06
0
0
046
1
0.
005
1
-
0
.
9
0.
33
0.
1
Gen2 Bus4
46
2.
63
0.
05
0.
1
0.
06
0
0
0.
46
1
0.
005
1
-
0
.
9
0.
33
0.
1
Gen3 Bus9
46
2.
63
0.
05
0.
1
0.
06
0
0
0.
46
1
0.
005
1
-
0
.
9
0.
33
0.
1
Table-5: P
O
WER SYSTEM
ST
ABI
L
IZ
ER (PSS
) IN
PU
T DAT
A
Type: P
SS1A
Gen
e
rato
r
ID
VSI
KS
VSTM
ax
VSTMin
VTMin
TDR
A1
A2
T1
T2
T3
T4
T5
T6
Gen1
SPE
E
D
3.
15
0.
9
-
0
.
9
0
0.
2
0
0
0.
76
0.
1
0.
76
0.
1
1
0.
1
Gen2
SPE
E
D
3.
15
0.
9
-
0
.
9
0
0.
2
0
0
0.
76
0.
1
0.
76
0.
1
1
0.
1
Gen3
SPE
E
D
3.
15
0.
9
-
0
.
9
0
0.
2
0
0
0.
76
0.
1
0.
76
0.
1
1
0.
1
3.
IMPLEME
N
TATION
OF SVC AND
PSS
SVCs are
p
a
rt o
f
t
h
e Flex
i
b
le AC t
r
an
smissio
n
system
d
e
v
i
ce family, regu
latin
g vo
ltag
e
and
stab
ilisin
g
th
e syste
m
. Th
e te
rm
"static"
refers to
th
e fact that th
e SVC h
a
s n
o
m
o
v
i
n
g
p
a
rts (o
th
er th
an
circu
i
t
brea
ker
s
an
d
di
sco
n
n
ect
s,
w
h
i
c
h
d
o
n
o
t
m
ove
u
n
d
e
r
no
r
m
al
SVC
ope
r
a
t
i
on)
. T
h
e S
V
C
i
s
an a
u
t
o
m
a
t
e
d
im
pedance m
a
tchi
n
g
de
vi
ce, desi
g
n
e
d
t
o
bri
ng t
h
e sy
st
em
cl
oser t
o
u
n
i
t
y
po
we
r fact
o
r
. I
f
t
h
e po
we
r sy
st
em
'
s
reactiv
e lo
ad
i
s
cap
acitiv
e
(lead
ing
)
, th
e SVC will use re
acto
r
s
(u
su
ally in
th
e fo
rm
o
f
Th
yrist
o
r-Contro
lled
Reactors) to c
ons
um
e VARs
from
th
e syste
m
, loweri
ng the system
vo
ltage. Unde
r
inductive (la
ggi
ng)
co
nd
itio
ns, th
e cap
acito
r b
a
nk
s are au
t
o
m
a
t
i
cally
switch
e
d in
, th
u
s
p
r
o
v
i
d
i
ng
a h
i
gh
er syste
m
v
o
ltag
e
. Th
ey
also
m
a
y be placed nea
r
high and ra
pi
dly va
rying loa
d
s, s
u
ch as arc furn
a
ces, whe
r
e the
y
can s
m
ooth flicker
v
o
ltag
e
. It is kn
own
th
at th
e
SVCs
with
an
au
x
iliary
inj
ectio
n
o
f
a su
itable sig
n
a
l can
co
n
s
i
d
erab
ly i
m
p
r
ove
th
e d
y
n
a
m
i
c st
ab
ility p
e
rforman
ce o
f
a
p
o
wer system
. It
is o
b
s
erv
e
d
th
at SVC co
n
t
ro
ls can
sign
ifi
can
tly
influe
nce nonlinear system
behavi
or es
pecially under
hi
gh-st
r
ess operat
ing conditions
and increa
sed SVC
gains.By rapi
dl
y controlling t
h
e
voltage
and
reactive
powe
r ,an SVC
can c
ont
ribute to t
h
e
enhancem
ent of t
h
e
po
we
r sy
st
em
dy
nam
i
c perfo
rm
anance.N
o
r
m
al
ll
y
, vol
t
a
ge regul
at
i
o
n i
s
t
h
e pri
m
ary
m
ode of co
nt
r
o
l
, an
d
th
is i
m
p
r
ov
es
v
o
ltag
e
stab
ility an
d
tran
sien
t
stab
ility. Ho
wev
e
r
, th
e co
n
t
rib
u
tion
of an
SVC to
th
e
d
a
mp
ing
of t
h
e system
oscillation res
u
lting
from
voltage regula
tion alone is us
ually s
m
all; supplem
entary control is
n
ecessary to
ach
i
ev
e
sign
ifican
t d
a
m
p
in
g.[2
]
A com
m
onl
y
used t
o
pol
o
g
y
o
f
a svc s
h
ow
n i
n
fi
g
.
(
b
)
.
C
o
m
p
ri
ses a pa
ral
l
e
l
com
b
i
n
at
i
on o
f
TC
R
and
fixce
d
capacit
o
r.it is basically a shun
t connected static var ge
nerator/a
b
so
r
b
er
.w
h
o
se
out
put
i
s
a
d
ju
st
ed t
o
ex
ch
ang
e
cap
a
citiv
e o
r
i
n
du
ctiv
e curren
t
so
as to
m
a
in
ta
in
o
r
con
t
ro
l sp
ecific p
a
ram
e
ters o
f
electrical po
wer
sy
st
em
,t
y
p
i
cal
ly
bus
v
o
l
t
a
ge
.
The reactive powe
r
i
n
jection of
a
SV
C
c
o
n
n
ect
ed t
o
b
u
s
k i
s
gi
ven
by
B
svc
=B
c
-B
L
; th
e sy
m
b
o
l
B
c
and B
L
are t
h
e respective
susc
eptance
of th
e
fixce
d
capacit
o
r a
nd
TCR.it is also
i
m
p
o
r
tan
t
t
o
no
te th
at a sv
c do
es
no
t
exc
h
a
n
ge real
power
with
th
e system
.
The sm
al
l
si
gnal
dy
nam
i
c
model
of a
SVC
i
s
sho
w
n i
n
fi
g.
(c).
∆
B
svc
i
s
defi
ned as
∆
B
c
-
∆
B
L
.t
he di
ffe
r
e
nt
i
a
l
equat
i
o
n
fr
om
t
h
i
s
bl
ock
di
a
g
ram
can easi
l
y
be
defi
ned
as
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
APE
I
S
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:
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2-8
7
9
2
C
o
m
b
i
n
e
d
O
p
e
r
at
i
o
n of
SVC
,
PS
S an
d Inc
r
e
a
si
n
g
Ine
r
t
i
a
o
f
Mac
h
i
n
e
f
o
r Pow
e
r Syst
em
(
B
abl
es
h
K
u
m
a
r
J
h
a)
19
∆
1
∆
1
∆
∆
∆
∆
.
∆
1
∆
∆
.
∆
1
∆
∆
K
v
,T
v1
,T
v2
are th
e g
a
in
and
time co
n
s
tan
t
o
f
v
o
ltag
e
con
t
roller resp
ectiv
el
y.T
svc
is
the time constant associated
with
SVC
respo
n
s
e.T
m
is th
e
v
o
ltag
e
sen
s
ing
circu
it ti
m
e
co
n
s
tan
t
.
Th
e effectiv
eness of an
SVC in
en
h
a
n
c
ing
syst
em
stab
ility d
e
p
e
nd
s
on
lo
catio
n of t
h
e SVC.To
d
e
term
in
e a suitab
l
e lo
catio
n
for SVC ,wh
e
re th
e vo
ltag
e
swing
are gretest with
ou
t
th
e SVC
is o
n
bu
s-9
i
n
gi
ve
n t
e
st
sy
st
e
m
fi
g.(a).
Svc
c
ont
rol
m
odel
w
h
i
c
h
has
bee
n
use
d
i
s
s
h
ow
n
bel
o
w i
n
fi
g.(c
).
An
SVC
com
p
rising a fi
xed capacitor and a thyr
i
s
tor-controlled reactor
is c
onsi
d
ere
d
for
en
h
a
n
cem
en
t o
f
th
e syste
m
s
t
ab
ility .th
e
rati
n
g
o
f
th
e SVC is assu
m
e
d
to
b
e
1
5
0
Mv
ar
cap
acitiv
e and 1
50
Mv
ar i
n
du
ctiv
e .Th
e
v
o
ltag
e
reg
u
l
ator
g
a
in is set at
10
t
o
pr
ov
id
e a
1
0
%
slo
p
e
i
n
th
e co
ntr
o
l r
a
ng
e.
Po
wer sy
stem
stabilizer
Th
e
b
a
sic of a
p
o
wer system
stab
ilizer (PSS) is to
ad
d d
a
m
p
ing
to
t
h
e g
e
nerato
r o
s
cillatio
n
b
y
u
s
ing
auxiliary stabi
lizing signal(s
).T
o
provi
de
dam
p
ing, the st
abilizer m
u
st
produce a
com
pone
nt of
el
ectrical
to
rq
u
e
i
n
ph
ase with
th
e
ro
tor sp
eed
v
a
riati
o
n. Th
is
is achiev
e
d
b
y
m
o
d
u
latin
g
th
e
g
e
n
e
rato
r
ex
citatio
n so
as
t
o
de
vel
o
p a c
o
m
pone
nt
o
f
e
l
ect
ri
cal
t
o
rq
u
e
i
n
p
h
ase
wi
t
h
r
o
t
o
r s
p
ee
d
devi
at
i
o
n.
Sha
f
t
spee
d, i
n
t
e
g
r
al
o
f
po
we
r an
d t
e
r
m
i
n
al
freq
u
e
n
cy
are am
ong
t
h
e com
m
onl
y
use
d
i
n
p
u
t
si
gnal
s
t
o
P
SS.
[
4
]
.
PSS
ba
sed
on
sha
f
t
spee
d signal has bee
n
used s
u
ccess
f
ully since the m
i
d-
1960s
.a technique devel
o
ped
t
o
deri
ve a stabi
lizing
si
gnal
f
r
om
m
easurem
ent
of
shaft
s
p
eed
of
a sy
st
em
. A
m
on
g t
h
e i
m
port
a
nt
co
nsi
d
e
r
at
i
on i
n
t
h
e desi
gn
of
equi
pm
ent
for
t
h
e m
easurem
ent
o
f
s
p
eed
de
vi
at
i
on i
s
t
h
e
m
i
nim
i
zat
i
on of
n
o
i
s
e cau
se
d
by
sha
f
t
r
u
n
out
a
n
d
ot
he
r ca
uses.
[
3
]
-[4]
t
h
e
al
l
o
w
a
bl
e l
e
vel
o
f
n
o
i
s
e i
s
de
pen
d
e
nt
o
n
i
t
s
fr
eq
uency
.
F
o
r
n
o
i
s
e f
r
eq
ue
ncy
b
e
l
o
w
5
H
z, th
e lev
e
l
m
u
st b
e
less
th
an
0
.
02
%, si
n
ce sign
ific
a
n
t
cha
nges i
n
t
e
rm
i
n
al
vol
t
a
ge
can
be p
r
od
u
ced
by
low-freque
ncy changes
in
t
h
e field vo
l
t
a
ge
.
The a
p
pl
i
cat
i
on
of
sha
f
t
s
p
ee
d
stab
ilizer to
t
h
erm
a
l u
n
it requ
ires a
carefu
l
con
s
i
d
eratio
n
of th
e effects
on
to
rsi
o
n
a
l
o
s
cillatio
n
.
Th
e stab
ilizer, wh
ile d
a
m
p
in
g
t
h
e ro
t
o
r
oscillation, ca
n cause insta
b
ility of th
e torsional m
odes.
One a
p
proac
h
su
ccessfully used to circ
um
vent the
p
r
ob
lem is to
sen
s
e th
e sp
eed
at a lo
catio
n o
n
th
e sh
aft near th
e no
d
e
s o
f
th
e critical
to
rsion
a
l m
o
d
e
s [5
]-
[6].In addition
,an electronic filter is use
d
i
n
stabilizi
ng
path to attenuate the torsional c
o
m
ponents.T
h
e
powe
r
syste
m
stab
iliz
er(PSS1
A
) m
o
d
e
l wh
ich h
a
s
b
een used
with th
e
g
e
n
e
rators
is sho
w
n
b
e
low in fi
g
.
(d).
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92
IJA
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.
3
,
No
. 1, A
p
ri
l
20
14
:
15
–
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20
4.
SIMULATION RESULT
AN
D D
I
SCU
SSION
Th
e
Etap
Tran
sien
t
Stab
ility An
alysis is d
e
si
g
n
e
d to
i
n
v
e
stig
ate th
e system
d
y
n
a
mic respo
n
s
e
disturba
nce. T
h
e program
models
dynam
i
c
characteristic
s
of a
po
wer
sy
st
em
, im
pl
em
ent
s
t
h
e u
s
er
-de
f
i
n
e
d
events
and acti
o
n, s
o
lves
the
syste
m
network e
quation
and m
ach
in
e d
i
fferen
tial equ
a
tion
in
teractiv
ely to
fi
n
d
out
syste
m
and m
achine response i
n
tim
e domain.
In
t
h
is pap
e
r
we d
i
scuss th
e tran
sien
t stab
ilit
y p
e
rform
a
n
ce with
PSS,SVC
an
d
b
y
i
n
creasin
g
i
n
ertia
o
f
sy
n
c
hro
nous m
ach
in
e.Th
e tran
sien
t stab
ility i
m
p
r
o
v
e
men
t
is no
t on
ly su
fficien
t
b
y
u
s
ing
o
n
e
m
e
t
h
od
.
So
here
we use these three com
b
ine
d
m
e
thod for im
proving
stability. Here we use
ACCELERATE
D
GAUSS-
SEIDEL
for in
itial lo
ad
flow calcu
lation
.
In
wh
ich
m
a
x
i
m
u
m
n
u
m
b
er of iteratio
n
i
s
2
000
and
So
lu
ti
on
Precision
fo
r t
h
e In
itial LF
is 0
.
000
001
An
d
Tim
e
In
cremen
t fo
r In
teg
r
ation
Step
s
(
Δ
t)
is 0
.
010
0 an
d
acceleration fa
ctor for the init
ial load
flow is
1.45.Intial inertia of th
e insta
lled
m
achine was 4 M
W
-Sec/MVA
and afte
r inc
r
e
a
sing its inerti
a is
7 M
W-Se
c
/MVA.Ine
r
tia of the
m
achine
is not s
o
m
u
ch inc
r
ease
d
.
Because
after in
creasing
in
ertia o
f
th
e
m
ach
in
e ro
to
r
will b
e
h
a
v
i
er
.so
th
at it is k
e
pt always with
in li
mit as co
n
s
ideri
ng
its reliab
ility
an
d
econ
o
m
y. Here
u
s
ed
PSS with
g
i
v
e
n
d
a
ta as in
tab
l
e-5
with
test syste
m
Fig
(
a). Th
e
electro
m
ech
an
ical o
s
cillatio
n
for g
e
n
e
rato
r electrical p
o
w
er is redu
ced
as well as th
e stead
y state p
o
wer i
s
also
enh
a
n
c
ed as seen
in
fig
-
(e).o
s
cillation
in
term
in
al
cu
rren
t and
fi
eld
cu
rren
t is also
redu
ced
an
d
th
e
mag
n
itu
d
e
of
field
curren
t
is also
redu
ced as seen
i
n
Fi
g
(
g
)
&Fig.(h
)
.Field
vo
ltag
e
o
f
Gen
-
1
is initiall
y
o
s
cillated
b
u
t
after so
m
e
ti
me it is
co
n
s
tan
t
an
d
wit
h
in
lim
it
as sh
own
i
n
fig.(f).i
f
on
ly in
ertia o
f
g
e
nerato
r is
increase
d
then
field
voltage
was does
not cha
nge
.
The differe
n
t plot for Gen-1. Whe
n
a three
pha
se fa
ult on bus
-3 at 0.5 se
c and cleare
d
at 1 sec are
sho
w
n bel
o
w
i
n
fi
g.
(1
)
(2)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
APE
I
S
SN
:
225
2-8
7
9
2
C
o
m
b
i
n
e
d
O
p
e
r
at
i
o
n of
SVC
,
PS
S an
d Inc
r
e
a
si
n
g
Ine
r
t
i
a
o
f
Mac
h
i
n
e
f
o
r Pow
e
r Syst
em
(
B
abl
es
h
K
u
m
a
r
J
h
a)
21
(3
)
Fi
g(e
)
El
ect
ri
c
a
l
po
we
r
of
Ge
n-
1
(1
)
onl
y
i
n
e
r
t
i
a
i
s
in
creased
(2) im
p
l
e
m
e
n
tatio
n
of
p
ss an
d in
ertia (3)
i
m
p
l
e
m
en
tatio
n
o
f
in
ertia ,p
ss &sv
c
(1
)
(
2
)
Fi
g(
f)Fi
e
l
d
vol
t
a
ge o
f
Ge
n-
1
(
1
)i
m
p
l
e
m
e
nt
at
ion
o
f
i
n
ert
i
a
&
p
ss
(2
)i
m
p
l
e
m
e
nt
at
i
on
o
f
i
n
e
r
t
i
a
,pss a
n
d
s
v
c.
(1
)
(
2
)
(
3
)
Fi
g(
g)
t
e
rm
i
n
al cu
rre
nt
o
f
Ge
n
-
1
(
1
)
o
nl
y
i
n
ert
i
a i
s
in
creased
(2) im
p
l
e
m
en
ta
tio
n
o
f
in
ertia
&sv
c
(3
)
i
m
p
l
e
m
en
tatio
n
o
f
in
ertia,p
ss&sv
c
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
252
-87
92
IJA
P
E Vol
.
3
,
No
. 1, A
p
ri
l
20
14
:
15
–
2
2
22
(1
)
(2)
(3
)
Fi
g(
h)
Fi
el
d c
u
r
r
ent
of
Ge
n
-
1
(
1
)
o
nl
y
i
n
ert
i
a
i
s
i
n
creased (2
)
i
m
p
l
e
m
en
tatio
n
o
f
in
ertia and p
s
s (3
)
i
m
p
l
e
m
en
tatio
n
o
f
in
ertia ,p
ss &sv
c
.
5.
CO
NCL
USI
O
N
In
t
h
is p
a
p
e
r a n
e
w
op
ti
m
a
l c
o
n
t
ro
l ap
pro
a
ch
fo
r im
p
r
ov
emen
t o
f
tran
si
en
t stab
ility.Here Tran
sient
stability Perform
ances of the
m
u
lti
machine syste
m
by using coordi
nated ef
fect
of
PSS, SVC and by
i
n
creasi
n
g i
n
er
t
i
a
of m
achi
n
e an
d co
n
v
ent
i
o
nal
m
e
t
hod ha
s
bee
n
com
p
are
d
.
An
d
we see
t
h
at
bet
t
e
r r
e
sp
on
s
e
in
term
s o
f
electro
m
ech
an
ical o
s
cillatio
n
h
a
s
b
e
en
ac
h
i
ev
ed in case
of
with
PSS and
SVC.Th
e pro
p
o
s
ed
meth
o
d
also
has th
e adv
a
n
t
ag
e
o
f
con
s
i
d
erin
g
t
h
e
p
e
rm
issib
l
e system
co
nd
itio
ns.
In g
e
n
e
ral, an
alytical
an
alysis and
si
m
u
latio
n
results u
s
ing
E-TAP software
sh
ow t
h
at th
e
p
r
op
o
s
ed
and
g
ood
flex
ib
ility for
tran
sien
t stab
ility
i
m
p
r
o
v
e
m
e
n
t
.
REFERE
NC
ES
[1]
P.
L.
Dandeno,
A.
N Karas,
K.
R. McCl
y
m
ont, an
d W.Watson. ”Effect of High-
Speed Rec
tifi
e
r Ex
ica
tion S
y
stem
o
n
Generator
Stab
il
it
y
Lim
its”,
IEEE Trans.
,Vol. PAS-87. Pp. 190-
201, 1968
.
[2]
W.Watson and G.Manchur. “Experien
ce wi
th supplementar
y
Damping
Signals
for Generator
Static Exicatio
n
S
y
s
t
em
”,
IEEE Trans.
, Vol. PA
S-92. Pp. 199-20
3, 1973
.
[3]
W
.
W
a
tson and M.E Coultes
.
”Stati
c Exi
c
t
e
r Sta
b
iliz
i
ng Signals
on Large Gene
r
a
tors-Mechan
ic
a
l
Problem
s”,
IEE
E
Trans.
, Vol. PA
S-92. Pp. 204-21
1, 1973
.
[4]
P.Kundur ,D.C.Lee
and H.M.
Z
e
in E
L
-Din.
”Power s
y
stem
stab
ilizer fot
therm
a
l units:Anal
y
t
i
c
al Techniques
an
d
On-Site Validation”,
I
E
EE Trans.
,Vol. PAS-100.
Pp. 81-95, 1981.
[5]
M.L. Shelton
,
R
.
F Winklem
en, W.A M
ittelstand
t, and W.L Bell
erb
y
. ”Bonn
evil
l
e
Power Adm
i
ni
stration 1400 MW
Braking R
e
sistor
”,
I
E
EE Trans.
,
VOL. PAS-94. Pp. 602-611
, 197
5.
[6]
P.K. I
y
ambo, R. Tzonova. “Tran
s
ient
Stability
A
n
aly
s
is of the I
E
EE
14-Bus Electrical
Power S
y
stem”,
IEEE Conf.
,
2007.
Evaluation Warning : The document was created with Spire.PDF for Python.