In
te
r
n
ation
a
l Jou
rn
al
o
f Po
we
r
Elec
tron
ic
s an
d
D
r
ive S
y
stem
(IJ
PED
S
)
V
o
l.
1
1
,
N
o.
1, Mar
ch 20
20,
p
p.
350~
3
5
8
IS
S
N
: 2088-
86
94,
D
O
I
:
10.11
59
1
/ij
ped
s
.
v11
.
i
1.pp
3
50-
35
8
3
50
Jou
rn
a
l
h
o
me
pa
ge
:
ht
tp:
//i
j
p
eds.i
a
esco
re
.com
Frequ
e
ncy response anal
ysis f
or transfo
rmer
tap
changer
d
a
mage detection
S.
A
l
-
A
m
e
r
i
1
, A.
A
. Alawady
2
,
M. F
. M. Y
ousof
3
,
H
.
A
h
m
a
d
4
,
A
l
i
.
A
.
S
a
l
em
5
,
M
.
A
.
Talib
6
1
,
2,
3,
4,
5
D
e
p
a
rtm
e
n
t
of El
ectrical & E
lect
ro
n
i
cs Eng
ineeri
n
g
,
Un
i
versi
t
i
T
u
n
Hu
s
s
e
in O
nn
M
a
l
a
y
sia
,
M
a
l
a
y
sia
2
D
e
p
a
rtm
e
n
t
o
f Com
p
uter Techn
i
cal
En
g
in
eerin
g
,
C
oll
e
ge of
Tech
ni
cal E
ngi
neering
Isl
a
mi
c U
n
iversi
ty, Iraq
6
Ten
a
g
a
N
asi
o
n
a
l
Berhad
Research
, M
alay
sia
Art
i
cl
e In
fo
ABSTRACT
A
r
tic
le hist
o
r
y
:
Re
ce
i
v
e
d
A
ug
7,
201
9
Re
vise
d O
c
t
2
7
,
20
1
9
Ac
ce
p
t
ed
No
v
1
3
,
2
019
Fre
q
ue
n
c
y
re
sponse
a
n
a
l
y
s
is
(
F
R
A)
m
e
t
ho
d
ha
s
b
e
e
n
p
ro
v
e
n
to
d
e
t
ect
t
h
e
tran
sf
o
r
m
e
r
windi
ng
dam
a
ge.
How
e
ver,
t
here
i
s
n
o
p
ract
ical
s
tud
y
wh
ich
inv
e
st
ig
a
t
e
s
t
h
e
d
a
m
a
g
e
s
o
n
tran
sfo
r
me
r
ta
p
c
h
a
n
g
e
r
e
v
e
n
t
h
ough
i
t
h
a
s
a
hi
gh
f
ail
u
re
r
ate.
H
ence,
t
h
i
s
p
a
per
i
nves
t
igat
es
n
o
r
m
a
l
an
d
f
a
ulty
tran
sf
o
r
m
e
r
t
a
p
chan
ger
us
ing
F
R
A.
T
h
e
F
R
A
m
ea
s
u
rem
e
n
t
s
co
nd
uct
ed
us
in
g
fo
ur
d
iff
e
ren
t
t
est
co
nfi
g
u
r
atio
ns.
Als
o
,
no
rm
al
t
ap
c
han
ge
r,
p
itt
in
g
a
n
d
cok
i
n
g
t
ap
c
h
a
n
g
er
c
o
n
t
act
w
e
r
e
inv
e
st
ig
ated.
In
a
d
d
i
tion
to
F
R
A
m
easu
r
e
m
en
t,
w
in
d
i
n
g
r
es
is
t
a
nce
m
easu
r
em
en
t
h
a
s
been
c
o
n
d
u
ct
ed.
T
h
e
tran
s
f
o
r
m
e
r
t
u
rn
r
ati
o
m
easu
r
em
ent
also
c
on
d
u
cted
t
o
id
entify
t
he
t
aps
po
siti
on
s
.
T
h
i
s
s
t
u
d
y
res
u
lts
s
i
g
n
i
f
i
can
t
t
o
u
n
d
erstand
th
e
ef
f
ect
o
f
pitti
ng
a
nd
cok
i
n
g
t
ap
c
han
g
er
o
n
t
h
e
t
r
ansf
o
r
m
e
r
f
r
equen
c
y
res
p
o
n
se.
Th
e
r
esults
sh
ow
ed
t
hat
p
i
t
t
i
n
g
h
a
s
a
sl
ig
ht
i
n
f
lu
ence
on
t
he
f
req
u
en
c
y
r
es
po
ns
e.
Howe
ve
r,
c
ok
in
g
sh
ows
a
hu
ge
v
a
r
ia
tio
n
i
n
lo
w-fre
q
u
e
nc
y
re
spo
n
s
e.
T
h
i
s
ef
f
ect o
bs
erved duri
n
g
th
e w
i
ndin
g
res
istance
me
as
urem
en
t.
K
eyw
ord
s
:
Coki
ng
F
r
equenc
y
re
spons
e
ana
l
ys
ia
Pitt
ing
Tap
cha
nge
r fa
ul
t
Tran
sfo
r
mer
t
u
rn
rat
i
o
Th
is
is a
n
o
p
en acces
s a
r
ti
cle u
n
d
e
r t
h
e
CC
B
Y
-S
A
li
cens
e
.
Corres
pon
d
i
n
g
Au
th
or:
Sal
e
m
Mg
amm
a
l
Awad
h
N
asser
Al
-
A
meri
Depa
rtem
ent o
f
E
lectr
i
c
a
l a
n
d
Electro
n
i
cs
E
n
g
ine
e
ri
n
g
,
University T
un Husse
in
O
n
n
Ma
l
ays
i
a,
P
a
rit
Raja,
86
4
00,
M
a
l
a
y
s
i
a
.
Em
ail:
mga
m
m
a
l10
@
gm
ail.
com
1.
I
N
TR
OD
U
C
TI
O
N
Tr
ansform
e
r
s
a
r
e
use
d i
n
the
tr
a
nsm
i
ssi
o
n
a
n
d
d
i
s
tri
b
ut
ion
sys
t
em
s t
o
ste
p
up
a
n
d
dow
n t
h
e
vo
lta
ges.
D
u
rin
g
o
pera
ti
ona
l
li
fe
time
,
t
ra
n
s
f
o
rme
r
s
are
exp
o
se
d
t
o
f
ail
u
r
e
s
.
These
fai
l
ur
es
c
o
u
l
d
b
e
d
u
e
to
o
verl
oade
d,
ea
rth
q
u
a
ke,
a
n
d
mis
h
an
d
l
e
d
u
ri
ng
trans
p
ortat
i
on.
O
t
h
er
e
xam
p
l
e
s
a
re
t
ran
s
f
o
rme
r
w
i
ndi
ng
d
e
f
o
r
ma
t
i
on
,
in
su
la
ti
o
n
d
e
g
r
a
da
ti
on,
a
nd
tra
n
sf
orme
r
bus
h
i
n
g
s.
S
t
a
tis
t
i
c
a
l
s
tu
di
e
s
r
e
port
e
d
by
C
IGRE
p
resen
t
ed
t
hat
t
a
p
cha
nge
r
h
a
s th
e
hi
g
h
e
s
t
perc
e
n
ta
ge
5
6% of t
h
e
t
r
ans
f
orm
e
r fa
il
u
res [
1
]
.
I
n
o
rder
t
o
i
n
v
e
stiga
t
e
the
tra
n
sf
o
r
me
r
tap
c
h
an
ge
r
fa
ilure
,
th
e
r
e
a
r
e
few
me
thods
s
uc
h
as
d
ynam
i
c
resista
n
ce
m
e
a
sure
me
nt
(
D
R
M)
[
2,
3
].
T
he
p
revi
o
u
s
pa
pe
r
s
i
n
us
i
n
g
D
R
M
f
o
r
t
a
p
c
h
a
n
g
e
r
d
i
a
g
n
o
s
i
s
d
i
d
n
o
t
pro
v
i
d
e
a
n
e
x
p
la
na
tio
n
o
n
t
he
e
f
f
ec
t
of
v
ario
us
o
f
fa
i
l
u
r
e
s
on
the
freque
nc
y
resp
on
se
[
2,
4
].
T
he
c
on
tac
t
pro
b
lem
s
i
n
t
h
e
D
ETC
c
oul
d
be
i
n
v
es
ti
ga
te
d
u
s
i
n
g
w
i
nd
i
ng
res
i
st
an
c
e
me
a
s
u
r
emen
t
an
d
ex
cit
a
tio
n
c
u
rre
n
t
me
asure
m
e
n
t
[
5
,
6].
These
two
m
e
tho
d
s
c
ons
ide
r
ed
a
s
a
con
v
en
t
i
o
n
a
l
t
e
s
t
.
O
n
t
h
e
o
t
h
e
r
h
a
n
d
,
f
r
e
q
u
e
n
c
y
response
a
nalys
i
s
(F
R
A
)
c
o
n
s
i
d
e
r
ed
a
s
a
m
oder
n
m
eth
o
d
.
Also,
t
h
e
r
e
i
s
a
g
e
n
e
r
a
l
a
g
r
e
e
m
e
n
t
t
h
a
t
F
R
A
i
s
sens
iti
ve
t
o
t
h
e
m
e
c
h
anica
l
c
han
g
e
s
w
i
t
hin
the
tra
n
sf
orme
r
[7,
8].
Ther
e
a
r
e
several
st
u
d
ies
in
o
rde
r
t
o
i
n
v
e
st
i
g
at
e
t
h
e
t
r
a
n
sfo
r
mer
t
a
p
ch
ang
e
r
fau
l
t
s
u
si
ng
F
RA.
Th
e
i
n
f
l
u
e
n
c
e
o
f
ta
p
c
h
anger
on
F
R
A
i
s
in
ves
tiga
t
e
d
.
H
o
w
e
ve
r,
t
his
s
t
ud
y
o
n
ly
v
ar
y
i
ng
t
he
t
a
p
c
ha
nger
setup
[9].
A
l
s
o,
S
.
B
an
aszak
i
n
[
1
0
]
,
t
h
e
p
a
p
e
r
prese
n
t
e
d
a
st
u
d
y
on
t
h
e
i
n
fl
u
e
nc
e
of
t
ap
c
ha
nger
p
o
s
i
t
i
on
on
t
he
F
RA
.
Re
fer
e
nce
[11]
i
nve
st
iga
t
e
t
h
e
effec
t
Evaluation Warning : The document was created with Spire.PDF for Python.
Int J
P
o
w
E
l
e
c
&
D
ri S
yst
IS
S
N
:
2088-
86
94
Freq
uenc
y re
s
p
o
n
se
a
n
a
lys
i
s fo
r tra
n
s
f
orm
e
r
ta
p cha
n
g
er
dam
age
de
tec
t
ion (S. Al
-
A
m
e
ri)
35
1
of
f
a
u
l
t
y
t
a
p
c
han
g
er
o
n
F
R
A
me
asure
m
e
n
t
.
H
ow
ever
,
thi
s
s
tu
dy
i
n
v
e
s
t
i
g
a
t
e
s
t
h
e
f
a
u
l
t
y
t
a
p
c
h
a
n
g
e
r
b
a
s
e
d
o
n
sing
le
p
hase
t
ransform
er
.
The
stu
dy a
l
so
e
xa
m
i
nes fau
l
t
y
t
a
p
c
h
an
ger
usi
n
g
ope
n
circu
i
t t
e
st o
nl
y.
Thi
s
p
ap
er
i
n
v
est
i
g
at
es
t
h
e
e
f
f
ect
o
f
f
a
u
l
ty
t
a
p
c
h
a
ng
er
o
n
a
t
hre
e
-pha
se
d
i
s
tri
b
ut
ion
t
r
a
n
sf
orme
r
us
i
n
g
F
R
A
.
T
h
e
t
hree
-p
hase
d
istri
b
ut
ion
tra
n
sform
e
r
i
s
l
o
c
ated
a
t
a
l
o
c
a
l
p
o
w
e
r
u
t
i
l
i
t
y
r
e
s
e
a
r
c
h
c
e
n
t
e
r
.
I
t
i
s
11
/0.
4
3
3
kV
and r
a
ted a
t
50
0
k
V
A
.
Ther
e
are
thre
e
tap c
ha
n
g
e
r
c
o
n
d
i
t
i
on
s in
ves
t
i
g
a
t
e
d
i
n t
h
is pa
p
e
r
w
hi
c
h
a
r
e
norm
a
l,
p
i
tti
ng
a
n
d
c
ok
i
n
g
ta
p
c
h
a
nge
r
c
o
n
t
ac
t.
T
he
m
ea
su
r
e
m
e
nt
i
s
c
o
ndu
ct
e
d
b
a
s
ed
on
a
n
e
nd
t
o
en
d
o
p
e
n
circ
u
i
t,
a
n
e
n
d
to
e
nd
s
h
ort
c
i
rcu
it,
c
a
p
ac
i
t
ive
inte
r-w
in
d
i
ng,
a
n
d
i
n
duc
tive
i
n
ter-w
i
n
d
i
ng
t
e
s
t
s.
T
hi
s
stud
y
verifie
s
t
he
t
r
a
nsform
er
w
ind
i
n
g
i
n
he
al
thy
con
d
i
t
i
on
usin
g
tur
n
ra
t
i
o
tes
t
a
n
d
w
i
n
d
i
ng
resista
n
ce
t
e
s
t.
T
he
s
i
g
n
i
f
i
c
a
n
c
e
o
f
t
h
i
s
s
t
u
d
y
s
h
o
w
s
t
h
e
c
a
p
a
b
i
l
i
t
y
o
f
F
R
A
t
o
d
e
t
e
c
t
t
h
e
fa
ult
y
t
r
a
ns
for
m
er
t
ap
c
han
g
e
r.
I
n
add
i
tio
n,
it is t
o im
pro
v
e
t
h
e
i
n
sp
ect
i
on an
d
i
n
te
r
p
reta
t
i
o
n
o
f
the
t
r
a
nsform
er
f
ai
lures.
2.
FREQ
U
E
NCY
RE
S
P
ON
S
E
AN
A
L
Y
S
I
S
F
r
eque
nc
y
re
sponse
a
n
a
l
y
s
is
i
s
a
w
e
ll-u
s
e
d
t
ec
hn
iq
ue
t
o
d
i
a
g
nos
i
s
m
ec
h
a
ni
c
a
l
ch
an
g
e
s
in
t
he
trans
f
or
me
r
w
i
nd
ing
[1
2,
13].
Basica
lly,
the
ma
i
n
f
u
n
c
t
i
o
n
of
F
R
A
i
s
t
o
d
eterm
i
ne
t
he
d
am
age
on
the
acti
v
e
parts
o
f
t
he
t
r
a
nsform
er
(
w
i
nd
ing,
l
ea
ds,
and
c
o
r
e
).
A
lso,
it
h
as
b
ee
n
repor
te
d
t
h
a
t
F
RA
can
d
e
t
ec
t
no
n-
me
cha
n
ic
al c
h
a
nge
s suc
h
a
s t
e
m
p
era
t
ur
e an
d
m
o
istur
e
c
on
t
e
n
t
o
f
w
i
ndi
ng
insu
l
a
t
io
n.
F
RA
i
s
a
c
o
mpe
r
h
i
n
s
i
v
e
tech
n
i
q
u
e
to
a
s
s
ess
t
h
e
tra
n
s
f
orm
e
r
c
ond
i
t
i
o
n
[14].
F
R
A
is
a
c
o
mp
ara
t
iv
e
t
e
st
w
hi
ch
r
equ
i
red
ref
e
re
n
c
e
d
a
t
a
to
c
om
pare
w
it
h.
T
h
e
re
fore,
a
ny
d
i
ffe
r
enc
e
s
betw
e
e
n
t
he
t
w
o
m
e
a
sure
ment
r
es
po
nse
s
u
gge
st
e
d
t
h
e
re
i
s
fa
u
l
t
[8,
15].
The
FRA
me
asurement
i
s
c
o
n
d
u
c
t
ed
by
app
l
yi
ng
a
sma
l
l
s
i
n
u
s
o
i
d
a
l
A
C
v
ol
ta
ge
s
i
gna
l
at
d
iffe
ren
t
fre
que
nc
ies.
T
hi
s
si
g
n
al
i
s
inje
cte
d
a
t
o
n
e
e
nd
of
t
he
t
ra
ns
for
m
e
r
w
i
nd
i
n
g
an
d
m
e
a
s
ur
e
d
t
he
o
u
t
pu
t
s
i
gna
l
a
t
the
ot
her
e
n
d
o
f
t
he
w
i
n
d
i
n
g
a
s
sh
ow
n in
F
i
g
ure
1.
T
he
r
a
t
io be
twee
n
the m
easure
d
a
n
d
t
he i
n
j
e
c
t
ed
s
i
g
nal
s
i
s
ca
l
l
e
d
t
he
t
ra
n
s
fer
fu
nc
ti
on.
T
he
t
r
a
ns
fer
func
tio
n
c
a
rr
i
e
s
inf
orm
a
ti
o
n
r
e
g
ard
i
n
g
t
he
c
a
p
aci
ta
nc
e,
r
esis
tance
,
mu
t
u
a
l
i
ndu
ct
an
ce
,
i
ndu
ct
a
n
ce
,
o
f
t
h
e
w
i
n
din
g
and
co
re
.
Th
e
r
e
f
o
re
,
ch
ang
e
s
in
t
he
t
ransf
o
rme
r
w
i
n
din
g
and
core
w
i
l
l
al
ter
its
t
rans
fe
r
fun
c
ti
o
n
.
The
tra
n
sfe
r
f
u
n
c
t
i
o
n
w
i
l
l
s
how
t
he
se
c
ha
n
g
e
s
i
n
t
h
e
am
pl
i
t
u
d
e
a
n
d
pha
se
of
t
he
m
easur
ed si
gna
l [1
6].
F
i
g
u
r
e
1
. The
m
ea
sur
e
m
e
nt c
onf
i
g
ur
at
i
o
n
fo
r
t
h
e
teste
d
t
r
a
nsfor
me
r
[
5
]
The
r
e
ar
e
fo
ur
m
ea
surem
e
nt
c
on
nec
t
i
o
ns
b
e
t
w
e
en
t
he
t
ra
n
s
form
er
and
F
R
A
e
q
uipm
en
t
.
T
hese
a
r
e
end
t
o
e
n
d
o
pe
n
circ
ui
t,
e
nd
t
o
e
n
d
s
h
o
rt
c
irc
u
it,
c
a
p
ac
it
ive
i
nt
er-wi
n
d
i
ng
,
an
d
i
ndu
ct
iv
e
i
n
t
e
r-wi
nd
i
n
g
[1
5
]
.
The
F
R
A
i
n
strum
e
nt
c
a
n
o
b
t
ain
t
h
e
v
o
l
ta
g
e
t
r
a
nsfer
fu
nc
tio
n
o
f
t
h
e
w
i
nd
ing
fr
om
2
0
H
z
t
o
2
MH
z
.
T
hi
s
fre
que
nc
y
ra
n
g
e
i
s
t
he
n
d
i
v
i
ded
i
n
t
o
s
u
b
-
b
and
s
i
n
order
t
o
i
nte
r
p
ret
the
F
R
A
re
sul
t
s.
T
he
se
s
ub-ba
n
d
s
a
r
e
di
ffe
re
nt
f
r
o
m
one
t
ra
ns
form
er
t
o
ano
t
her.
T
he
F
RA
s
ub-
b
a
nd
s
de
p
e
n
d
o
n
t
h
e
siz
e
o
f
t
h
e
tra
n
s
f
orm
e
r,
t
ype
a
n
d
arrang
e
m
e
n
t
.
I
n
l
i
t
e
ra
tu
re,
t
h
ere
are
se
v
e
ra
l
st
at
is
ti
c
a
l
m
e
t
h
o
d
s
p
r
o
po
se
d
to
i
n
t
e
r
pre
t
t
he
F
RA
me
asure
m
e
n
t
.
F
or
e
xam
p
le,
t
h
e
cor
r
ela
t
io
n
c
o
effic
i
e
n
t
(C
C
)
i
n
[
1
7
,
18],
the
a
b
s
o
l
u
te
s
u
m
o
f
l
o
gari
thm
i
c
er
ror
(AS
LE) [19,
20].
3.
T
A
P CHANGE
R
F
AULT
S
A
st
a
t
i
s
t
i
ca
l
st
ud
y
o
n
t
r
a
nsfo
rm
e
r
f
a
i
l
u
re
s
w
a
s
con
duc
te
d
in
[
1
].
I
t
ind
i
cate
d
t
hat
tap
c
h
an
ger
fa
u
l
t
o
c
c
u
p
i
e
s
t
h
e
h
i
g
h
e
s
t
p
e
r
c
e
n
t
a
g
e
i
n
p
o
w
e
r
t
r
a
n
s
f
o
r
m
e
r
f
a
i
l
u
r
e
s
.
I
t
w
a
s
r
e
p
o
r
t
e
d
b
y
C
I
G
R
E
t
h
a
t
5
6
%
o
f
p
o
w
e
r
trans
f
or
me
r
faul
ts
i
n
the
N
e
t
h
e
r
lan
d
s
w
e
re
c
ause
d
by
ta
p
c
h
a
n
ge
r.
H
en
c
e
,
t
h
e
st
udy
o
f
f
au
lt
o
n
p
o
w
er
trans
f
or
me
r
ta
p
c
h
a
nge
r
i
s
a
m
ajor
c
o
n
c
e
rn
i
n
re
cen
t
yea
r
s
[2
1]
.
Th
e
r
e
a
r
e
th
re
e
OLTC
s
co
n
t
act
d
eg
rad
a
ti
on
st
a
g
es
a
c
c
rue
d
.
These
a
r
e
fi
l
m
on
the
c
o
n
t
a
c
t
surfa
ce,
h
i
g
h
l
o
c
a
l
t
em
per
a
ture
(
cok
i
n
g
)
on
t
he
c
on
t
a
c
t
s
u
r
fac
e
and
fina
l
l
y
c
o
ntac
t
fai
l
u
re
d
ue
t
o
ov
e
r
hea
t
i
n
g
(p
i
t
te
d
s
pot
s
or
p
i
tti
ng).
O
t
her
fa
i
l
ure
s
c
a
n
o
c
c
u
r
s
u
c
h
a
s
Evaluation Warning : The document was created with Spire.PDF for Python.
ISS
N
:
208
8-
8
6
9
4
I
n
t
J
P
o
w
Elec
&
D
r
i
S
y
st
V
ol
.
11,
N
o.
1
,
M
a
r
2020
:
35
0
–
35
8
35
2
c
h
em
i
c
a
l
o
r
m
e
c
h
ani
c
a
l
w
e
a
r
,
f
or
i
ns
ta
nc
e,
o
x
i
da
t
i
o
n
,
c
oking,
m
ec
han
i
ca
l
wea
r
,
frett
i
n
g
an
d
therm
a
l
de
f
o
r
m
ati
o
n
s
(
pi
t
t
i
n
g)
[
22]
.
3.
1.
Cok
i
ng
Cok
i
ng
i
s
a
c
he
mica
l
pr
o
c
ess
when
car
bo
n
is
e
x
t
rac
t
e
d
from
t
h
e
su
rro
un
ding
o
i
l
o
f
p
o
w
er
t
r
an
sfo
r
me
r
an
d
a
t
t
a
ch
ed
o
n
t
h
e
t
a
p
ch
ang
e
r
co
nt
act
.
T
h
e
pro
c
es
s
sta
r
te
d
w
i
t
h
t
h
i
n
o
il
fi
l
m
f
or
ma
t
i
o
n
o
n
t
h
e
c
o
n
t
a
c
t
.
S
ubse
que
n
t
l
y
,
it
l
e
a
d
s
to
i
ncr
easi
ng
o
f
t
a
p
c
o
n
ta
ct
r
e
si
st
an
ce
.
T
h
e
r
e
f
o
r
e,
i
t
p
r
od
u
c
e
s
m
o
r
e
h
eat
.
Mor
e
over
,
t
h
i
s
phe
nome
n
o
n
a
c
tiva
t
e
s
w
he
n
tem
p
er
atur
e
c
l
o
s
e
to
2
00
°
C
a
bo
v
e
.
Then,
the
s
u
r
r
ound
i
n
g
o
i
l
wi
ll
f
o
r
m
c
o
kin
g
on
t
a
p
c
h
a
ng
er
c
on
t
a
c
t
[
22].
B
a
s
ed
o
n
t
h
e
p
r
e
v
io
us
s
t
u
dy
i
n
l
i
t
er
at
ur
e
c
o
k
i
ng
i
n
f
l
ue
nc
e
t
h
e
c
o
n
t
a
c
t
r
esista
nc
e
and
h
i
gher
it
s
tem
p
er
a
t
ur
e
[
11,
23]
.
3.
2.
Pitt
i
n
g
P
itt
ing
c
o
r
r
os
ion
is
l
oc
al
ize
d
s
m
a
ll
c
a
v
i
tie
s
or
h
oles
f
or
me
d
i
n
m
e
ta
ls
s
uc
h
a
s
c
o
p
p
er
.
Ty
pi
c
a
l
ly,
pi
t
t
i
n
g
a
ccr
ue
d
i
n
t
he
a
d
v
a
n
c
e
d
s
t
age
s
o
f
a
g
in
g
a
n
d
o
n
t
he
c
ha
n
ge
o
ver
s
e
l
e
ct
or
c
onta
c
t
s
[4]
.
B
e
s
ide
s
o
f
t
h
e
i
n
c
r
e
a
s
e of
c
arb
o
n
,
s
ma
l
l
p
itte
d
spo
t
s are
c
r
ea
t
e
d
whi
c
h
can
b
e
d
eve
l
o
p
e
d
i
nt
o
dee
p
h
o
l
e
s
.
4.
ME
TH
O
D
OLO
G
Y
4.
1.
Tr
an
sform
er
con
f
igurat
ion
Th
is
e
xp
e
r
ime
n
ta
l
st
u
d
y
i
s
c
on
d
u
cte
d
o
n
a
thr
ee-
phase
d
i
s
tri
b
u
t
ion
tra
n
sform
e
r
with
d
e-
ener
gi
z
e
d
tap
cha
n
ger
(
D
ETC)
r
a
te
d
a
t
1
1
/
0.
43
3
kV
,
5
0
0
kV
A
a
s
s
h
o
w
n
i
n
F
i
gu
r
e
2
(a)
.
T
h
e
t
ran
s
f
o
rmer
v
ecto
r
gro
up
a
nd
c
o
n
f
i
g
ur
at
i
on
a
l
so
a
r
e
s
ho
w
n
i
n
F
i
g
u
r
e
2
(
b
)
.
T
he
w
indi
ng
ta
ps
a
r
e
c
o
nnec
t
e
d
t
o
t
h
e
tap
c
h
a
n
ger
se
le
ctor
a
s
s
how
n
i
n
F
ig
ur
e
2(
c)
.
Tap
c
h
a
nge
r
se
t
t
i
n
g
i
s
pr
ov
i
d
e
d
i
n
Ta
b
l
e
1
.
It
b
r
i
efly
e
xp
la
i
n
s
the
t
a
p
c
h
a
nge
r
n
u
m
b
e
rs
a
nd
t
h
e
t
a
p
s
windi
ng
c
o
n
n
e
ct
ed
.
Fo
r
e
x
ampl
e
,
T
ap
1
c
onn
e
c
t
s
ta
p
n
u
m
b
er
4
a
n
d
5
t
hus,
se
le
c
t
i
n
g
t
h
e
w
h
o
l
e
w
i
nd
i
n
g
w
h
i
l
e
Ta
p5
c
o
nne
c
t
s
t
a
p
n
u
m
be
r
2
an
d
7
w
h
ic
h
o
n
l
y
s
el
ec
t
s
t
he
m
i
n
i
m
um
a
m
oun
t
of
t
ur
n
i
n
the
w
i
n
d
i
n
g.
H
ow
eve
r
,
in
t
hi
s
tr
ansf
or
m
e
r,
t
he
t
a
p
s
n
u
mbe
r
s
a
r
e
not
m
a
r
ked
i
n
t
h
e
t
a
p
c
han
g
er
s
e
l
ec
tor
.
T
his
is
b
ec
au
se
t
he
t
r
a
ns
for
m
er
h
a
s
b
ee
n
un-
t
a
n
k
e
d
bef
o
r
e
a
n
d
t
he
t
a
p
lead
s
h
a
ve
b
ee
n
r
e
m
o
ved.
F
or
t
h
i
s
r
e
aso
n
,
tur
n
s
r
a
ti
o
tes
t
n
e
e
d
t
o
b
e
pe
r
f
o
r
m
ed
t
o
i
d
en
t
i
f
y
t
he
t
a
p
s
nu
m
b
ers.
(a)
(b
)
(c)
F
i
gur
e
2.
(
a)
E
xpe
r
i
me
nt
e
d
5
00
kV
A
di
s
t
r
i
b
u
t
i
on
t
r
a
n
sf
or
m
e
r
(
b
)
tr
ansf
o
r
mer
w
i
n
d
i
ng
c
o
n
f
ig
ur
at
io
n
(
c
)
ta
p
c
h
an
ger
sele
c
t
or
D
ETC
p
o
s
i
t
i
on
co
ntr
o
l
4.
2.
Tr
an
sform
er
tu
rn
r
atio
m
ea
sur
e
me
nt
Turn
r
a
t
i
o
t
e
s
t
is
c
on
d
u
cte
d
f
or
a
ll
trans
f
or
me
r
t
a
ps.
It
i
s
to
i
n
d
i
c
a
t
e
t
h
e
V
r
a
t
i
o
f
o
r
a
l
l
t
a
p
s
.
T
h
i
s
m
e
a
s
ur
em
ent
w
i
l
l
h
e
l
p
to
i
d
e
nti
f
y
t
h
e
t
a
ps
num
ber
s
w
hic
h
a
r
e
n
o
t
m
a
rk
e
d
i
n
t
h
e
ta
p
cha
n
g
e
r
se
lec
t
o
r
.
It
i
s
al
so
t
o
v
a
lid
ate
t
h
e
c
ond
iti
on
o
f
a
ll
t
h
r
ee
p
ha
se
s
wi
ndi
ng
.
Thi
s
is
b
y
c
o
m
p
ari
ng
t
h
e
m
easur
ed
a
nd
c
a
l
c
u
la
te
d
Vra
t
i
o
.
It
h
as
a
s
i
m
pl
e
con
n
ec
t
i
o
n
wh
e
r
e
th
e
i
npu
t
si
gn
a
l
i
nj
ec
te
d
a
t
HV
term
inal
a
nd
the
o
u
t
p
u
t
s
i
gna
l
m
e
a
s
ur
ed
a
t
t
h
e
LV
s
ide.
T
he
t
ur
n
r
a
t
i
o
tes
t
w
as
c
o
n
duc
te
d
usi
n
g
TR
F
-
10
0
w
h
ic
h
i
s
m
anu
f
ac
t
u
r
e
d
by
V
a
ng
uar
d
I
nstr
ume
n
t.
T
o
ca
l
c
ul
a
t
e
t
h
e
t
u
r
n
r
atio
f
r
o
m
the
tr
ans
fo
rmer n
am
ep
l
a
t
e
:
HV
pha
se
V
rat
i
o
LV
pha
se
(
1
)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t
J
P
o
w
Elec
&
D
r
i
S
y
st
I
S
S
N
:
2088-
86
94
F
r
e
q
uency
res
p
o
n
se
a
n
a
l
y
s
i
s
f
o
r tra
n
s
f
orm
e
r ta
p c
h
a
nge
r dam
age
de
tec
t
i
on (
S
.
Al
-
A
m
e
ri)
35
3
In
a
d
el
ta con
nectio
n
,
V
line
= V
phas
e
,
how
e
v
er
,
t
o
ge
t
V
line
i
n
s
tar
conne
c
t
ion
V
line
= V
ph
a
s
e
×√
3
.
The
TRF-
10
0 als
o
c
alcu
la
te
t
he p
e
r
ce
nt
a
g
e
diffe
r
e
n
ce
(Δ
%
)
betwee
n t
he
calc
u
la
t
e
d
an
d
me
asur
e
d
v
ol
t
a
ge
r
ati
o
.
4.
3.
T
a
p
c
h
an
ge
r
f
a
u
l
t
s
f
ab
r
i
c
a
t
i
on
C
o
pp
er
t
a
p
e
i
s
u
sed
to
i
n
v
e
sti
g
at
e
th
e
e
f
f
ect
o
f
fa
ult
y
t
a
p
c
h
a
n
g
e
r
o
n
F
R
A
m
e
a
s
ur
em
ent.
T
he
m
os
t
c
o
mm
on
ta
p
c
h
an
ger
fa
il
ur
e
s
a
r
e
c
o
k
i
n
g
a
n
d
pit
t
i
ng.
T
o
p
e
r
f
or
m
c
o
k
i
ng,
c
ha
r
c
oa
l
d
u
s
t
h
a
s
b
ee
n
gl
ue
d
o
n
a
piec
e
o
f
c
o
ppe
r
tape
.
Bas
ica
l
l
y
,
t
h
e
gl
ue
a
p
p
l
ie
d
o
n
t
he
c
o
pper
s
u
r
f
a
ce
d
id
n
ot
a
f
f
ect
t
he
c
on
t
act
b
e
cau
se
i
t
ha
s
bee
n
d
r
i
e
d
b
efor
e
us
i
ng.
O
n
the
o
t
h
e
r
ha
nd,
t
o
for
m
p
it
t
i
n
g
c
orr
o
si
o
n
o
n
the
c
o
p
p
e
r
t
a
p
e,
h
am
mer
and
c
h
ise
l
w
er
e
us
e
d
.
The
nor
m
a
l,
c
ok
i
n
g
a
n
d
pi
tti
n
g
c
oppe
r
t
a
pe
a
r
e
s
h
ow
n
i
n
F
igur
e
3.
T
he
c
op
pe
r
ta
pe
s
a
r
e
use
d
t
o
co
n
n
e
c
t
t
w
o
t
a
p
s
i
n
D
ETC
b
y
h
o
l
d
in
g
us
in
g
G
-
c
l
am
p
as
s
h
ow
n
i
n
F
i
gur
e
2
(c).
Fi
g
u
r
e
3
.
T
h
e
f
a
b
ri
cat
e
d
c
oppe
r
t
a
p
e
s.
F
r
o
m
l
e
ft
,
n
o
r
ma
l
,
p
it
ti
ng
a
nd
co
k
i
n
g
.
4.
4.
F
RA me
asuremen
t
conn
ection
Acc
o
rding
to
C
IGRE
W
G
A
2
.26
[15]
,
IEEE
C
5
7
.
146
st
a
ndar
d
[
8]
a
nd
I
EC
6
00
7
6
-
1
8
[
24]
t
her
e
a
r
e
f
o
u
r
m
ea
sur
e
m
e
nt
c
on
fi
g
u
r
a
t
i
o
n
s
be
tw
ee
n
the
t
r
an
sf
or
m
e
r
a
nd
F
R
A
e
qui
pm
ent.
T
he
y
ar
e
en
d
to
e
nd
o
p
en
c
i
r
c
u
it,
e
nd
to
e
nd
s
h
o
r
t
c
ir
cu
it,
c
a
p
aci
t
i
ve
i
nte
r
-
w
in
d
i
ng,
a
n
d
i
n
duc
t
i
ve
i
n
t
e
r
-
w
ind
i
ng.
I
n
t
h
e
en
d
to
e
nd
o
pe
n
c
i
r
c
u
it,
t
he
s
i
g
nal
is
i
nje
c
te
d
at
o
ne
e
n
d
o
f
the
wi
nd
ing
a
n
d
m
easur
e
t
h
e
ou
t
p
u
t
s
igna
l
a
t
a
no
t
h
er
e
nd
o
f
t
h
e
sa
me
w
i
n
di
n
g
w
hile
t
he
l
ow
v
o
l
tage
w
i
n
d
i
ng
is
o
pen.
T
he
e
nd
t
o
e
n
d
s
h
o
r
t
circ
u
it
m
e
a
s
ur
em
ent
i
s
s
im
ilar
t
o
en
d
t
o
e
nd
ope
n
c
i
rc
ui
t
but
t
h
e
l
o
w
v
ol
t
a
ge
w
i
ndi
ng
t
ermi
n
a
ls
a
re
s
hort
e
d
.
T
h
e
c
a
p
aci
tiv
e
i
n
t
e
r-
wi
ndi
ng
co
nn
e
c
t
i
on
i
s
co
ndu
c
t
ed
b
y
ap
ply
i
n
g
th
e
in
pu
t
si
gn
al
a
t
t
h
e
h
i
g
h
v
o
ltage
s
ide
a
nd
m
e
a
s
ur
e
the
o
u
t
pu
t
v
o
l
t
a
ge
a
t
t
he
l
ow
v
ol
ta
ge
s
ide.
T
he
i
nd
uc
t
i
ve
i
nter
-
w
in
din
g
c
o
n
n
e
c
t
i
o
n
i
s
q
u
i
t
e
s
imilar
t
o
c
a
p
a
c
i
t
i
ve
i
n
t
e
r-win
di
n
g
,
bu
t
t
h
e
hi
g
h
v
o
l
t
a
ge
a
n
d
l
ow
vol
ta
ge
w
in
d
i
ng
s
ar
e
gr
ou
nde
d.
4.
5.
Win
d
ing
resis
tan
ce
measu
remen
t
T
h
e
win
d
in
g
re
si
st
an
c
e
me
a
s
u
r
emen
t
is
c
ond
u
c
t
e
d
to
d
et
ermi
n
e
t
h
e
wi
nd
ing
re
si
st
an
ce
v
a
lu
e
.
I
t
i
s
be
lie
ve
d
t
h
a
t
c
ok
i
ng
in
t
a
p
c
han
g
e
r
i
ncr
e
a
s
es
t
he
t
o
t
a
l
w
in
din
g
r
e
s
i
s
tan
c
e
.
H
e
n
ce
,
t
h
e
win
d
i
ng
r
esi
s
t
a
n
ce
m
e
a
s
u
r
e
m
e
n
t
i
s
p
e
r
f
o
r
m
e
d
.
T
h
i
s
m
e
a
s
u
r
e
m
e
n
t
c
o
u
l
d
s
u
p
p
o
r
t
t
h
e
F
R
A
m
e
a
s
ur
em
ent.
T
h
e
w
in
d
i
n
g
r
e
s
ista
nc
e
m
e
ter
is
a
d
i
g
it
al
r
es
ista
nce
r
eadi
n
g
from
1
m
icro-ohm
t
o
50
0
o
hms
[
2
5]
.
W
i
nd
i
n
g
r
e
sis
t
a
n
ce
m
ea
sur
e
m
e
nt
i
s
c
o
n
duc
te
d
a
t
H
V
side
o
f
o
n
e
p
h
a
s
e.
5.
RESU
L
T
S
A
ND ANALY
S
IS
It
w
as
m
en
tio
n
e
d
ear
lier
t
h
a
t
t
ra
nsform
er
t
ur
n
ra
ti
o
m
easur
e
m
e
n
t
is
c
o
n
d
u
c
te
d
to
d
e
t
er
mi
ne
t
he
t
ap
s
pos
i
tio
ns.
The
r
e
ar
e
five
t
a
p
s
in
t
he
H
V
w
i
nd
i
ng
bu
t
t
h
e
y
a
r
e
n
o
t
m
ar
ke
d.
T
r
a
nsfor
m
e
r
t
ur
n
r
a
t
i
o
w
a
s
pe
rform
e
d
to
v
a
l
ida
t
e
i
f
t
he
v
o
lta
ge
r
a
t
i
o
o
f
a
ll
p
h
ases
i
s
in
go
od
c
o
ndit
i
on
.
Tabl
e
1
sh
o
w
s
t
h
e
cal
cu
l
a
t
e
d
vo
l
t
age
r
a
t
i
o.
F
r
o
m
the
r
e
su
l
t
s
of
v
o
l
ta
ge
r
a
t
i
o
a
n
d
c
ur
r
e
nt
v
a
lue
s
,
we
can
d
ete
r
m
i
ne
t
h
e
a
ct
ual
co
n
f
i
g
ura
tio
n
of
t
he
t
r
a
ns
for
m
e
r
w
indi
ng
a
nd
t
a
p
c
h
a
nger
pos
i
tio
n.
T
he
a
ctua
l
a
r
r
a
nge
m
e
nt
i
s
s
how
n
in
F
ig
ur
e
4(
a
)
a
nd
F
i
g
u
r
e
4
(b)
.
H
e
n
ce
th
e
ne
w
arrange
me
n
t
c
an
b
e
sum
m
a
rised
i
n
T
ab
le
1
.
Fur
t
he
r
in
ves
tiga
tio
n
on
t
h
e
c
o
n
d
it
i
o
n
o
f
a
l
l
phase’
s
v
ol
ta
ge
r
at
i
o
i
s
per
f
or
m
e
d
us
i
n
g
(
2
)
.
H
e
r
e
T
R
C
a
n
d
T
R
M
a
r
e
t
h
e
c
a
l
c
u
l
a
t
e
d
a
n
d
t
h
e
m
e
a
s
ur
ed
t
ur
n
r
a
ti
o
r
e
spe
c
t
i
v
e
l
y.
T
he
d
e
v
ia
tio
n
in
v
ol
ta
ge
r
ati
o
a
n
d
a
c
t
i
o
n
i
s
p
r
o
p
o
se
d
by
l
o
c
a
l
p
o
w
e
r
ut
i
lit
y
an
d
giv
e
n
in
Ta
b
l
e
2
.
Th
e
calc
u
l
a
ti
on
id
e
nti
f
i
e
s t
h
a
t
a
ll
p
h
a
se
s a
r
e
in
g
ood
con
d
i
t
i
on
a
n
d
t
h
e
re
s
ul
t
s
a
re sh
o
w
n
in T
a
b
le 3.
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
: 208
8-
869
4
Int J
Pow El
ec &
D
ri
S
yst
Vol.
11,
N
o.
1, Mar
202
0 : 35
0
– 35
8
35
4
(
a
)
(b)
F
i
gur
e 4.
The
D
yn
11 tra
n
sform
e
r
w
i
nd
i
n
g
con
f
ig
urat
io
n (a
)
t
h
e
n
ew
arrange
me
nt
(
b)
r
ig
ht
i
nse
t
i
s t
h
e n
e
w
sche
ma
tic
a
rr
a
nge
me
nts
Tab
l
e
1. The
tap
c
on
nec
tio
n
from
nam
epla
t
e
a
n
d
c
a
l
c
u
l
a
ted
vra
t
i
o
Ta
p
H
V
r
a
ting
Ta
p c
onne
c
t
i
o
n
L
V
r
a
ting
V
ra
t
i
o
Ca
lc
ul
a
t
e
d
1
1155
0
4-
5
C
-
D
433
46.
201
2
1127
5
5-
3
D-B
45.
101
3
1100
0
3-
6
B
-
E
44.
001
4
1072
5
6-
2
E-A
42.
901
5
1045
0
2-
7
A-F
41.
801
Tab
l
e
2
.
Resu
l
t
and
ac
t
i
o
n
s for
turn r
atio te
s
t
of
phase’
s
de
v
i
at
i
o
n
s
R
e
sult
C
o
n
d
i
tion indic
a
tor
Ac
tion
%
d
e
v
ia
tion <
0
.
3
G
ood
Norm
a
l
c
onditi
on,
c
ontinue
testi
ng
0.
3
≤
%
d
e
v
ia
tion <
0
.
5
Fa
ir
0.
5
≤
%
d
e
v
ia
tion <
0
.
7
P
oor
D
e
v
i
a
t
i
ons a
t
t
h
e
t
a
p
po
s
itions
w
ith
in
th
e
s
a
m
e
p
h
a
s
e
,
c
ontinue
o
th
e
r
t
e
s
t
s
t
o
find
the
fa
ul
t afte
r
re
p
a
ir
c
ontinue
t
est
i
ng.
%
d
e
v
ia
tion
≥
0.
7
Ba
d
%
100%
TR
T
R
M
C
dev
i
a
tions
TR
C
(
2
)
Ta
b
l
e
3.
The
e
rr
or in
volta
ge
ra
tio
b
e
t
w
e
e
n
t
h
e
m
ea
sured
and c
a
l
c
ul
at
ed
v
ra
t
i
o
Ta
p No
P
ha
s
e
R
P
ha
s
e
Y
P
ha
s
e
B
C
ondition
1
0.
071
0
.
084
0
.
017
good
2
0.
031
0
.
042
0
.
029
good
3
0.
016
0
.
002
0
.
075
good
4
0.
063
0
.
051
0
.
093
good
5
0.
110
0
.
098
0
.
151
good
5.1.
Fr
eque
nc
y
re
s
p
o
n
se
a
na
l
y
si
s re
sul
t
s
Th
e
FR
A t
e
st
were
p
e
rfo
rme
d
o
n
a
l
l
t
h
re
e
ph
as
es
o
f
th
e
t
r
a
n
sfo
r
m
e
r. H
ow
ever,
onl
y resu
lts from
RY
pha
se
i
s
pre
s
en
ted.
T
h
i
s
is
b
ec
a
u
se
t
he
o
t
h
er
pha
se
s
ha
ve
s
i
m
il
ar
r
esul
t
.
I
ni
t
i
a
l
ly,
the
co
p
p
er
t
ap
es
a
r
e
h
eld
o
n
the
tap
c
h
a
n
ge
r
usi
n
g
t
h
e
G
-
clam
p
a
t
v
er
y
t
i
g
h
t
c
o
n
n
ec
t
i
o
n
.
The
r
e
s
pon
s
e
i
s
pr
ese
n
t
e
d
in
F
ig
ure
5(a)
.
I
t
c
a
n
be
o
bserve
d
t
h
at
t
he
re
i
s
a
sm
all
va
ria
t
ion
at
l
ow
fre
que
nc
y
r
e
gi
on
a
t
a
b
o
u
t
10
0
H
z.
I
t
is
a
l
s
o
sh
ow
n
t
h
at
t
he
re
is
a
m
inor
s
hifti
n
g
t
o
w
a
rds
hi
gher
fre
que
nc
i
e
s
a
s
s
h
o
w
n
i
n
F
i
g
u
re
5
i
ns
et
.
O
n
t
he
o
t
h
e
r
h
an
d,
t
he
f
re
q
u
en
c
y
respo
n
se
f
or
n
orm
a
l,
p
i
tti
ng,
a
nd
c
o
kin
g
w
h
e
n
the
G
-
cla
m
p
i
s
n
o
t
ve
r
y
t
i
g
h
t
i
s
s
how
n
i
n
F
ig
ure
5(
b).
Th
is
i
s
qu
ite
p
oss
i
b
l
e
in
r
e
a
l
c
a
se
w
he
re
t
he
s
pr
ings
t
o
p
u
sh
t
ap
s
in
p
lace
h
a
s
w
e
a
ke
n.
I
n
t
h
e
r
e
sponse,
i
t
c
a
n
b
e
obs
erve
d
t
h
a
t
t
he
n
e
g
a
t
i
v
e
slo
p
e
fr
om
c
o
k
i
n
g
ha
s
a
h
uge
v
a
r
iat
i
on
a
t
low-freque
ncy
region
a
t
a
b
o
u
t
20Hz
to
2kH
z.
T
hi
s
is w
here
t
he inf
lu
e
n
ce of ind
uc
ti
ve ele
me
n
t
is o
b
ser
va
bl
e
.
It
c
o
u
l
d als
o
b
e
d
u
e
to
i
n
cr
easi
n
g
of
t
a
p
cha
nge
r
resist
a
n
ce.
H
ow
e
v
er, it c
o
u
l
d
be
s
e
e
n
a
sm
a
ll var
i
at
i
o
n
b
et
we
en
norma
l
an
d
p
i
t
t
i
ng
at
a
b
out
1
00Hz.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t
J
P
o
w
Elec
&
D
r
i
S
y
st
I
S
S
N
:
2088-
86
94
F
r
e
q
uency
res
p
o
n
se
a
n
a
l
y
s
i
s
f
o
r tra
n
s
f
orm
e
r ta
p c
h
a
nge
r dam
age
de
tec
t
i
on (
S
.
Al
-
A
m
e
ri)
35
5
F
i
gur
e
5.
E
nd
t
o
e
nd
o
p
e
n
c
ir
c
u
it
r
e
spo
n
se
o
f
RY
p
ha
se
a
t
ve
r
y
ti
ght
t
a
p
s
(
a
)
c
l
am
p
is
nor
m
a
l
pr
essur
e
(
b)
cl
amp
i
s
ti
ght
Com
p
ar
i
s
on
b
e
t
w
e
e
n
f
r
e
que
n
c
y
r
e
spo
n
se
s
of
nor
m
a
l,
p
it
t
i
n
g
,
an
d
cok
i
ng
fro
m
t
h
e
en
d
t
o
e
nd
s
ho
r
t
c
i
r
c
u
it
t
e
st
i
s
s
how
n
in
F
i
gur
e
6(
a
)
.
The
r
e
spo
n
se
s
h
o
w
s
t
hat
p
itt
i
ng
d
o
e
s
n
ot
g
ive
a
n
y
eff
e
c
t
c
ompa
r
e
t
o
t
h
e
r
e
spo
n
se
o
f
n
o
r
m
a
l
tap
c
h
a
nge
r
.
H
ow
ever
,
f
r
eque
nc
y
r
e
s
p
o
n
se
due
t
o
co
ki
ng
s
ho
ws
a
hug
e
v
a
r
i
at
io
n
a
t
l
o
w
-
f
r
e
que
n
c
y
r
e
g
i
on.
S
i
m
i
l
ar
t
o
end
t
o
e
n
d
ope
n
a
n
d
s
hor
t
c
i
r
c
ui
t
r
e
s
u
l
t
s,
t
h
e
i
nd
uc
t
i
ve
i
n
t
er
-
w
i
ndi
n
g
t
es
t
sh
ow
s
th
e
v
a
ria
tion
d
u
e
t
o
co
k
i
ng
o
f
t
ap
c
h
a
nger
o
c
cu
rs
a
t
lo
w-freq
u
e
nc
y
r
e
gi
o
n
.
The
in
duc
t
i
ve
i
nter
-
w
in
d
i
n
g
re
sp
on
s
e
i
s
sh
own
in
F
igu
r
e
6(b
)
.
Fi
n
a
l
l
y
,
t
h
e
ca
p
a
c
i
tiv
e
in
t
e
r
-
w
indi
n
g
t
es
t
i
s
u
nab
l
e
t
o
d
e
t
e
c
t
t
h
e
ta
p
c
h
a
nge
r
f
a
u
l
t
s
.
The
fr
eque
nc
y
r
e
sp
o
n
se
s
o
f
n
or
m
a
l,
p
i
t
t
i
n
g
,
an
d
c
o
k
i
ng
at
c
a
p
a
c
it
ive
in
ter-w
i
n
d
i
ng
m
e
as
urem
ent
c
o
n
f
ig
u
r
at
io
n i
s
pre
se
nte
d
i
n F
i
gure
6(c)
. No vi
s
ib
le
v
aria
tio
n
or
cha
n
ges be
t
w
ee
n
t
h
r
ee
re
spo
n
se
s.
(a)
(b
)
(c)
F
i
g
u
r
e
6
.
(
a)
E
nd
t
o
e
n
d
s
h
o
r
t
c
i
r
cui
t
r
e
s
po
ns
e
of
R
Y
phase
(
b)
I
nduct
i
v
e
i
n
ter
-
w
i
n
d
i
n
g
r
esp
onse
o
f
R
Y
ph
a
s
e
(
c
)
Capa
c
iti
ve
i
n
t
e
r
-
w
in
di
n
g
r
e
s
p
onse
o
f
R
Y
pha
se
5.
2.
Win
d
ing
resis
tan
ce
re
s
u
lts
The
w
i
nd
i
ng
r
e
sista
n
c
e
t
es
t
h
a
s
been
c
o
n
d
u
c
t
e
d
us
in
g
t
r
an
sfor
m
e
r
resist
a
n
ce
m
ete
r
m
od
e
l
W
RM-4
0
m
a
nuf
ac
t
u
r
e
d
by
V
a
ng
uar
d
I
ns
tr
um
ent
s
C
o.
T
he
w
i
ndi
n
g
r
e
s
is
tanc
e
m
eas
ur
e
m
e
n
t
is
p
r
e
se
n
t
e
d
i
n
Ta
bl
e
4.
I
n
the n
o
rm
al
t
a
p
c
han
g
er,
the
m
a
xim
u
m
wi
nd
ing
res
i
s
t
ance
i
s
a
t
p
h
a
s
e
R
w
h
i
c
h
is
a
b
o
u
t
1.
5
5
6
ohms.
W
hile t
he
wi
nd
ing
resi
sta
n
ce
o
f
t
h
e
t
a
p
ch
a
n
g
e
r
du
e
to
p
i
tti
ng
i
n
cre
a
se
d
a
b
o
u
t
0
.
0
1
oh
m
o
n
a
l
l
ph
a
s
e
s
.
Ho
we
v
e
r,
t
he
wi
nd
ing
re
si
st
a
n
c
e
i
n
c
re
as
es
a
t
mu
ch
h
i
g
h
e
r
v
a
l
u
e
wh
en
t
he
t
a
p
c
h
a
nger
expe
r
i
ence
f
a
u
lt
d
u
e
t
o
c
ok
in
g.
T
he
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
: 208
8-
869
4
Int J
Pow El
ec &
D
ri
S
yst
Vol.
11,
N
o.
1, Mar
202
0 : 35
0
– 35
8
35
6
wi
nd
i
n
g
res
i
st
an
c
e
a
t
ph
ase
R
sho
w
s
9
.
2
82
oh
ms
w
hi
ch
i
s
a
hu
g
e
val
u
e
c
o
m
p
are
wi
t
h
n
o
r
m
a
l
at
1
.
5
5
6
ohm
s.
A
d
d
iti
ona
l
l
y
,
the
co
o
k
i
n
g
ta
p
c
h
a
n
ger
co
ntac
t
w
a
s
da
m
a
ge
d
d
u
ri
n
g
the
e
xpe
rim
e
nt.
The
dam
a
ge
w
a
s
occ
u
rred
dur
in
g
t
a
k
i
n
g
t
he
m
easure
m
e
n
t
in
pha
se
B
.
F
o
r
t
h
i
s
r
ea
son,
t
he
r
e
s
i
s
ta
nc
e
of
p
hase
B
i
s
3.5
6
6
o
hms
w
h
ic
h i
s
n
ow
s
m
a
ller
t
h
a
n
r
es
ista
nce
o
f
p
has
e
s
R
an
d
Y
.
T
o
i
nve
st
iga
t
e
t
h
e
co
nd
i
t
ion of
t
r
a
nsform
er
w
in
di
n
g
,
the
perc
e
n
ta
ge
d
i
ffe
re
nc
e
of
w
in
din
g
r
e
s
i
s
ta
nc
e
betw
ee
n
p
h
a
s
e
s
can
b
e
cal
cul
a
t
e
d
us
ing
(3
).
H
ere
a
an
d
b
are
the
p
h
ases
i
n
t
r
ansf
o
r
me
r.
T
he
s
u
gges
t
e
d
a
c
tio
ns
b
ase
d
o
n
th
e
r
esis
t
a
nce
a
r
e
prov
ide
d
b
y
loc
a
l
pow
er
u
ti
lit
y
as give
n
in
Ta
ble 5.
T
he
m
easured resis
t
a
nc
e
s
ar
e
p
r
e
sente
d
i
n
Tab
l
e
6
.
T
h
e
r
esu
l
t
s
s
ugge
st
t
h
a
t
al
l
p
h
a
s
e
s
are
i
n
goo
d
con
d
itio
n
a
t
n
o
r
mal
a
n
d
pi
t
t
i
n
g
t
a
p
c
h
a
n
g
e
r b
u
t
in
a b
a
d
con
d
iti
o
n
w
he
n t
h
e
tap c
h
an
ger
has
cok
i
ng.
Ta
bl
e
4
.
Wi
ndin
g
re
si
st
an
ce
of
a
l
l
p
h
ases a
t
norm
a
l,
p
itt
i
n
g
an
d
cok
i
ng o
f
t
a
p
c
ha
n
g
er
Norma
l
(
Ω)
P
itting (Ω)
C
oking (Ω)
R
Y
B
R
Y
B
R
Y
B
1.
556
1.
547
1
.
535
1.
561
1
.
557
1.
556
9
.
282
6.
044
3
.
566
Tab
l
e
5.
R
e
s
ult
s
a
nd
a
c
tio
ns f
or w
ind
i
ng re
sista
n
c
e
te
s
t
Re
sult
i
n
oh
m
s
C
ondition
indic
a
tor
A
c
tion
%diffe
re
nc
e <
3
G
ood
N
o
r
m
a
l
c
ondi
tion,
c
ontinue
t
e
s
ting
3
≤
% diffe
re
n
c
e <
5
F
a
ir
5
≤
%
diffe
re
n
c
e <
7
P
oor
D
e
v
i
a
tions a
t
the
ta
p
positions
w
ithi
n
the
s
a
m
e
pha
s
e
,
c
onti
nue
o
th
e
r
t
e
s
t
s
t
o
find
the
f
a
ult a
f
te
r
re
p
a
ir
c
onti
nue
t
e
s
ting.
%
diffe
re
nc
e
≥
7
B
a
d
%
100
%
a
b
b
(
3
)
Tab
l
e 6.
The
per
centa
g
e
di
f
fe
re
nce
of r
esist
a
nce
betwee
n p
h
ase
s
Ta
p c
ondi
tion
Pha
s
e
s
(
R
v
s. Y)
Ph
as
e
s
(Y v
s. B)
Ph
a
s
es
(B
vs. R
)
Sta
t
e
Norm
a
l
0
.
582
0
.
782
1
.
368
G
ood
Pit
ting
0
.
257
0
.
064
0
.
321
G
ood
C
oking
5
3
.
574
69.
490
160.
29
2
Ba
d
6.
CONCL
U
S
ION
F
R
A
te
st
i
s
a
re
cog
n
i
zed
m
et
ho
d
t
o
d
e
t
ec
t
t
h
e
trans
f
or
me
r
wind
i
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PRG-I
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Int J
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:
2088-
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Freq
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35
7
REFE
RENCES
[1]
E.
G
.
R
.
J
o
n
g
e
n,
P
.
Mo
r
s
hu
is,
J.
S
mit
,
A
.
Jans
sen
,
"
A
st
at
i
s
t
i
c
al
a
pp
roach
t
o
p
r
o
c
ess
i
n
g
p
o
w
er
t
ran
s
f
o
rm
er
f
a
i
l
u
re
dat
a
,
"
1
9
t
h
I
n
t.
C
o
nf
.
E
l
e
c
tr
.
D
i
s
t
r
i
b
,
n
o.
V
i
e
nna,
07
36
,
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2
1-24,
2
00
7.
[2]
J.
J
.
E
r
b
r
ink
,
E
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Gu
l
s
k
i
,
J
.
J
.
S
m
it,
P
.
P.
S
eitz,
an
d
R.
L
e
i
c
h
,
"
E
x
p
erim
ent
a
l
m
ode
l
of
a
g
i
n
g
m
e
c
h
a
ni
sm
s
of
o
n
-
lo
ad
tap
chan
ger co
ntact
s," i
n
In
ter
nati
ona
l
Co
n
f
eren
ce
on
Con
d
itio
n
M
onit
o
r
i
ng a
nd Dia
g
n
o
sis
,
pp.
247
–2
50,
2
0
0
7
.
[3]
N.
C
in
c
a
r
and
G.
M
ilojev
ic,
"
O
n-l
o
ad
t
ap
c
han
g
er
t
esti
ng
m
e
th
od
s
,
"
vo
l.
8
,
n
o
.
su
pp
or
t@dv
-p
owe
r
.c
om
.,
p
p
. 1-8
,
19
91
.
[4]
J.
E
rb
rin
k
,
J
.
S
mit,
E
.
G
u
lski,
an
d
R.
L
eich
,
"Ex
p
eri
m
en
tal
m
o
d
el
f
or
d
iag
n
o
s
i
n
g
on
-lo
a
d
tap
chan
ger
co
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act
a
g
i
n
g
with
d
yn
am
ic
r
esi
s
tan
ce
meas
urem
ent
s
,"
i
n
20t
h Int
e
rn
a
t
ional
Conf
eren
ce
a
n
d
Exhi
bi
ti
o
n
o
n
E
l
ectricity
D
i
st
ri
b
u
t
i
o
n
,
p
p
.
1
-4, 20
0
9
.
[5]
S
.
C
h
a
rles,
G.
W
e
n
yu,
a
n
d
R
.
U
l
m
e
r,
"
D
i
agnos
ti
c
t
e
sti
n
g
an
d
m
o
n
ito
ri
ng
o
f
p
o
wer
tran
sf
orm
e
rs
,
K
now
t
h
e
con
d
i
t
io
n
o
f
y
our
t
ransf
o
rm
er,
"
O
M
IC
RO
N
,
vol.
L
2
673,
p
p
.
1
-36,
2
01
6.
[6]
A.
A
.
Salem
et
al
.
,
"Th
e
e
ffect
o
f
i
n
s
u
l
a
t
o
r
g
e
om
etrical
p
ro
f
ile
o
n
elect
ric
fiel
d
d
i
stri
bu
tio
ns,
"
Indo
nes
.
J.
E
l
ectr.
Eng.
C
o
mpu
t
.
Sc
i
.
,
v
o
l
.
14
,
n
o.
2
,
p
p
. 61
8
, 2
01
9.
[7]
Cig
r
e
W
G
A
2.26,
"
M
echan
ical
c
on
di
ti
on
ass
e
s
s
m
e
n
t
o
f
t
r
ansf
o
r
m
e
r
w
i
ndin
g
s
u
s
in
g
f
r
eq
uency
res
pon
se
a
naly
si
s
(Fra),"
Cigr
e
,
p
p
.
30-3
4
,
2
0
08.
[8]
"IE
E
E
gu
id
e
f
o
r
th
e
app
l
i
cati
on
and
in
terp
re
t
a
ti
o
n
o
f
f
r
equen
c
y
r
espo
ns
e
anal
ys
is
f
or
o
i
l
-im
m
e
rs
e
d
t
ransfo
rm
ers
IEEE po
wer
and
energy societ
y
,"
IEEE St
d
C57
.
149-2012
,
pp
.
1-72,
2
0
1
3
.
[9]
M
.
F
.
M
.
Y
o
u
s
o
f
,
C
.
E
k
a
n
a
y
a
k
e
,
a
n
d
T
.
K
.
S
a
h
a
,
"
A
n
i
n
v
e
s
t
i
g
a
t
i
o
n
o
n
t
he
i
nf
lu
e
n
ce
of
t
ap
c
han
g
e
r
on
f
req
u
en
cy
response
a
nalysi
s
,
"
i
n
IEEE 11th In
t
e
rn
atio
nal
Co
nf
erence on
t
h
e Pr
op
e
r
ti
es an
d Ap
p
l
i
c
a
t
ions
o
f
Diel
ectric
Materi
a
l
s
(ICPA
D
M
) an
,
p
p
. 9
63
-96
6
,
2
01
5.
[10]
S
.
B
anaszak
a
nd
W
.
S
z
o
ka,
"Infl
u
en
ce
o
f
a
t
ap
c
han
g
er
p
o
s
i
t
ion
on
t
he
t
ransform
er’s
f
requency
r
e
s
pons
e,"
i
n
Inn
o
va
tive M
a
t
e
ri
a
l
s a
n
d
T
echnolo
g
i
e
s
i
n
E
l
ect
rical
Engin
eeri
ng (
i
-M
IT
E
L
)
,
p
p
.
18-2
1
,
20
18.
[11]
S
.
A
l
-
A
m
e
r
i
,
M
.
F
.
M
.
Y
o
u
s
o
f
,
H
.
A
h
m
a
d
,
M
.
A
l
s
u
b
a
r
i
,
a
n
d
M
.
A
.
Ta
l
i
b
,
"
E
x
a
m
in
in
g
fa
ul
ty
t
r
a
ns
for
m
e
r
t
a
p
c
h
a
n
g
e
r
using
fr
e
q
u
e
nc
y
re
sp
on
se
a
na
lysis
,
"
in
2017 Internation
a
l Sy
mp
os
ium
on E
l
ectrica
l In
s
u
lating ma
t
e
ri
a
l
s
(
I
S
E
IM)
,
p
p
.
259-26
2,
2
0
17.
[12]
M
.
B
agheri
,
M.
S
.
Naderi
,
T.
B
lack
bu
rn,
B.
T
.
P
h
ung,
a
nd
Z
.
Li
u
,
"F
requen
c
y
resp
on
se
a
nal
y
si
s
to
r
ecogn
iz
e
in
du
ctance
variat
io
n
i
n
t
ran
s
f
o
rm
er
d
ue
t
o
intern
al
s
ho
rt
c
i
r
cu
it,"
1
0
t
h
In
t.
Power E
n
er
gy Conf
. IPE
C
2
012
,
pp
.
6
77-6
8
1
,
2
0
1
2.
[13]
J.
C
.
G.
A
ris
p
e
and
E
.
E
.
M
o
m
b
ell
o
,
"Detect
io
n
of
f
ail
u
res
wit
h
i
n
t
ran
s
f
o
rm
e
r
s
b
y
F
RA
u
sing
m
u
lti
r
esol
u
tion
deco
m
pos
it
io
n
,
"
IEEE T
r
ans
.
Powe
r Deliv.
,
vo
l.
29
,
n
o
.
3
,
p
p
.
11
2
7
-1
13
7,
2
01
4.
[14]
S
.
A
l
-
A
m
e
r
i
,
M
.
F
.
M
.
Y
o
u
s
o
f
,
N
.
A
z
i
s
,
S
.
A
v
i
n
a
s
h
,
M
.
A
.
T
a
l
i
b
,
a
nd
A
.
A
.
S
al
em
,
"M
od
eli
n
g
f
r
equ
e
ncy
res
pon
s
e
of
t
ran
s
f
o
rmer
w
indin
g
t
o
in
vest
ig
a
t
e
th
e
i
n
f
l
ue
n
ce
o
f
R
L
C
,
"
In
do
nes.
J.
E
l
ectr.
En
g.
Co
mput.
Sci.
,
vo
l.
1
4,
n
o
.
1
,
pp
.
2
19-2
2
9
,
2
0
1
9.
[15]
P
.
P
icher,
"
M
e
ch
ani
cal
c
ond
it
ion
ass
e
ssm
en
t
o
f
t
ran
s
f
o
rm
er
w
ind
i
n
g
s
u
sin
g
f
re
quen
c
y
r
e
sp
ons
e
an
aly
s
i
s
(
Fra),
"
C
i
g
r
e
,
E
v
al
u
a
ti
on
,
vol.
A2.
26,
pp.
3
0-3
4
,
2
0
0
8
.
[16]
O.
P
redl,
Flo
r
ian
,
"
In
terpret
a
ti
o
n
o
f
sweep
f
req
u
en
cy
r
esp
ons
e
analy
s
i
s
(
S
F
RA)
m
easurem
en
t
resu
lt
s
,
"
OMIC
R
O
N
ener
gy
, pp
.
1
-26
,
Au
s
tralia 20
1
6
.
[17]
G.
K
enn
e
dy
,
A.
M
cG
rail
,
and
J.
L
apw
o
rt
h,
"
Tra
n
sf
o
r
m
e
r
s
w
eep
f
re
qu
ency
r
es
po
ns
e
analy
s
is
(
SFRA),
"
En
e
r
g
i
ze
,
eepu
b
l
i
sh
ers
,
p
p
.
1
-12
,
2
007.
[18]
A.
I
slam
,
"
D
etecti
o
n
of
m
ech
ani
c
al
d
ef
orm
a
tion
in
o
ld
a
ged
pow
e
r
t
r
ans
f
o
r
m
e
r
u
s
ing
cro
ss
co
rrel
ati
o
n
co
-e
f
f
i
c
ient
anal
ys
is
m
e
t
ho
d,
"
En
e
r
g
y
Po
w
e
r
E
n
g.
,
v
o
l
.
0
3
,
pp
.
58
5-5
91,
S
ep
201
1.
[19]
A.
S
.
Mur
t
hy,
N.
A
zis,
S
.
A
l
-
A
m
e
ri,
M.
F
.
M.
Y
ousof,
J
.
J
a
s
n
i
,
an
d
M
.
A
.
Tali
b,
"
In
vestig
ation
of
t
he
e
f
f
ect
o
f
wi
nding
c
lam
p
in
g
s
t
ru
cture
on
f
r
eq
uen
c
y
r
e
s
pon
se
s
ig
nat
u
re
o
f
1
1
kV
d
i
s
t
r
ibuti
o
n
tran
sf
ormer,
"
E
n
er
gies
,
v
o
l.
1
1
, n
o.
9,
pp
. 1-1
3,
20
1
8
.
[20]
V.
B
ehj
a
t
an
d
M
.
M
ahv
i
,
"
S
t
a
tistical
a
pp
roach
f
or
i
n
t
erpret
atio
n
o
f
p
ow
er
t
ran
s
f
o
rmers
f
r
eq
uency
resp
on
se
a
naly
si
s
results,"
IE
T
S
c
i. Me
as
. T
e
c
h
n
o
l.
, v
ol
.
9
, no
.
3
,
p
p
.
3
67
-37
5
, 2
01
5
.
[21]
Y.
L
iu,
Z.
W
ang,
a
nd
P
.
J.
G
ri
ffi
n,
"
Arti
f
i
cial
i
nt
e
lligence
in
O
LTC
f
a
ult
diag
nos
is
u
s
i
ng
d
i
s
s
o
lv
ed
g
a
s
-in
-
o
i
l
inf
o
rmat
i
on," in
Powe
r
En
gin
e
e
r
i
n
g
So
c
i
e
t
y
Su
mme
r Me
e
t
in
g
(C
a
t
.
No
.
0
0C
H3
71
34
)
,
pp
. 1
93
–2
1
1
, 20
0
0
.
[22]
J.
H
il
le
rg
re
n
a
n
d
M.
L
in
da
h
l
,
"
O
n
mov
i
n
g
c
o
n
t
a
c
t
s
in
o
n-loa
d
t
a
p
chan
gers,
"
Mas
te
r Sc
i. Th
e
s
is
,
no
.
Ch
a
l
mer
s
Un
iv
e
r
sit
y
o
f
T
e
ch
no
lo
gy
ABB Co
mp
on
ent
s
G
¨
ot
ebo
r
g,
S
w
e
den
,
2
0
1
0.
[23]
J.
J
.
Sm
it,
"
O
n
-l
oad
ta
p ch
anger
di
ag
nosis
on
hi
gh
-volta
ge
p
o
wer tra
n
sform
e
r
s
usi
ng dyn
a
m
i
c r
e
sista
n
c
e
me
asure
m
e
n
ts
,"
T
e
c
h
nisc
h
e
Un
i
v
e
rsite
i
t
De
l
f
t,
Co
l
le
ge
v
oo
r
Prom
o
t
ie
s
,
2
01
1
.
[24]
IEC 60
07
6-
18
E
d
.
1
, "
Powe
r
tra
n
sfor
me
r
s
-
Pa
r
t 1
8
, ‘Me
a
s
ure
m
e
n
t
of f
requ
ency
resp
o
n
s
e’," 20
1
2
.
[25]
Do
bl
e
Vang
uard
,
"Win
d
i
ng
r
e
s
i
s
t
a
nce
o
h
m
m
e
ter,
W
RM
-40
|
Vang
uard
I
ns
trum
en
ts
C
o
m
pa
n
y
,
Inc.
,
"
2
00
9
.
[On
l
i
n
e].
Avai
lab
l
e
:
h
t
t
ps://w
w
w
.vangu
ard-in
st
ru
m
e
nt
s
.
com
/
cat
eg
ori
e
s/tran
sf
orm
e
r-wind
i
n
g
-res
i
st
ance-
m
e
ters/wrm
-4
0
. [A
ccess
e
d:
1
3
-
Dec-20
18
].
Evaluation Warning : The document was created with Spire.PDF for Python.
IS
S
N
: 208
8-
869
4
Int J
Pow El
ec &
D
ri
S
yst
Vol.
11,
N
o.
1, Mar
202
0 : 35
0
– 35
8
35
8
B
I
OGRAPHIES
O
F AUTHO
RS
S
a
l
e
m
Mg
amm
a
l
Awadh
N
a
s
ser
Al-A
m
e
ri
r
eceiv
e
d
B.
Eng.
i
n
Mech
atro
nics
E
n
g
i
n
eerin
g
fro
m
A
s
ia
P
acif
i
c
U
n
iversi
ty
(
A
P
U)
i
n
20
12
.
He
r
ecei
ved
M
.
E
n
g
.
i
n
El
ectrical
P
o
w
er
f
ro
m
U
n
i
v
ers
i
ti
T
un
Huss
ein
O
n
n
M
a
lay
s
i
a
(
U
T
HM
)
f
r
om
201
4
to
2
01
6.
C
urren
t
ly
h
e
i
s
pu
rsuing
P
h
.
D
.
D
e
gree
i
n
U
n
i
versi
t
i
T
u
n
Hu
sse
i
n
O
nn
M
alay
si
a.
H
is
r
e
s
earch
i
s
on
t
ran
sf
ormer
c
o
nd
it
io
n
m
o
n
i
tori
n
g
usin
g
FR
A.
A
h
m
e
d
Allaw
y
M
oh
amm
e
d
A
l
a
w
ady
rec
e
iv
ed
B
.En
g
.
i
n
E
l
ectri
ca
l
f
r
o
m
U
n
iv
e
r
si
ty
o
f
K
u
fa
,
Iraq
in
2
0
0
7
.
H
e
rec
e
iv
ed
M
.E
ng.
i
n
Elect
rical power
s
yst
e
m
f
r
o
m (SH
UATS
)
,
In
di
a
in
2
01
2.
H
e
i
s
a
l
ectu
r
er
a
t
t
h
e
Dep
a
rtm
e
n
t
o
f
Co
m
puter
T
echn
i
cal
E
ngin
e
e
r
i
ng
,
Coll
age
of
T
ech
ni
c
a
l
E
ngi
neeri
n
g
at
I
sl
amic
U
n
i
vers
ity,
Iraq
sin
ce
2
0
0
7
.
Current
ly
h
e
is
p
urs
u
i
ng
P
h
.
D
.
Degree
in
Un
ivers
i
t
i
T
un
H
u
s
sei
n
On
n
Ma
lay
s
ia. H
i
s
researc
h
i
s
on
m
otor
s
f
a
u
l
ts
d
e
t
ecti
on us
in
g
F
R
A.
M
o
hd
F
a
i
r
ouz
M
o
h
d
Y
o
u
s
of
r
ecei
ved
B.
Eng
.
(
El
ectri
cal)
and
M.
Eng
.
(El
ectrical)
bo
th
from
U
n
iv
ersi
ti
T
e
k
n
o
lo
gi
M
alay
si
a
(UT
M
)
i
n
200
8
and
20
10
,
res
p
ect
iv
el
y.
H
e
is
a
l
ectu
r
er
a
t
th
e
D
e
partm
e
n
t
o
f
El
ectrical
P
ow
e
r
E
n
g
in
eerin
g
at
U
nivers
it
i
T
un
Hu
sse
i
n
Onn
Malaysia
s
ince
2
0
0
9
.
H
e
r
eceiv
e
d
P
h
.
D
.
d
e
gree
f
r
o
m
T
he
U
ni
versit
y
o
f
Q
u
eensl
an
d
,
A
ust
r
ali
a
i
n
20
15
.
Cu
rren
tl
y
he
i
s
on
ind
u
stri
al
a
tt
a
c
h
m
ent
with
T
enag
a
N
a
sio
n
al
B
erh
a
d
Res
ear
ch
i
nv
ol
vi
ng
m
a
n
y
res
earch
pro
ject
s es
pecial
ly on
c
o
nd
it
io
n
mo
n
i
to
r
i
ng
o
f
tr
a
n
s
f
o
rm
er
.
H
u
ss
ein
Ahm
a
d
w
a
s born in
Mersi
ng, J
oho
r, M
alays
i
a. H
e ob
ta
i
n
ed
hi
s
B.
S
c
(Hons)
and
M
.
S
c
i
n
E
l
ectri
cal
E
ngine
eri
n
g
f
r
o
m
t
h
e
U
n
i
v
e
rsi
t
y
o
f
S
trat
hc
l
y
d
e
,
S
c
o
t
land
,
U
K
i
n
1977
a
nd
1
9
8
1
,
res
p
ecti
v
el
y
and
su
bs
equ
e
n
t
l
y
o
bt
ained
hi
s
P
h
D
deg
r
ee
in
h
ig
h
v
oltag
e
e
ngi
neeri
ng
fro
m
U
n
iv
ersi
ty
o
f
Man
c
hes
t
er
(
f
o
rm
er
ly
U
MI
S
T
)
in
1986.
C
urrently,
h
e
is
a
p
rof
e
ss
or
i
n
the
f
acul
t
y
of
E
lect
r
i
cal
E
ngi
n
eering,
i
n
Un
ivers
iti
Tun
Hussein
Onn
Mal
a
ys
ia.
H
i
s
research
i
nt
eres
ts
i
n
clu
d
e
li
ghtning
pro
t
ecti
o
n
,
g
ro
und
in
g
sy
st
em
,
l
o
w
voltag
e
p
ro
te
c
tion
,
a
nd
i
nsula
t
io
n
perform
ance.
A
l
i
Ahmed
Ali
S
a
l
e
m
(A
li.
A
.
S
a
l
e
m
)
w
as
b
o
r
n
in
S
ana’a,
Y
em
en
o
n
M
a
rch
1,
1
98
5.
H
e
receiv
e
d
M
.
En
g.
i
n
E
l
ectri
cal
P
ow
er
E
n
g
i
n
eering
f
r
o
m
U
n
i
versit
i
T
un
H
us
se
i
n
O
nn
M
al
aysi
a
(U
THM
)
f
ro
m
2
014
t
o
2
0
1
6
.
Cu
rren
tl
y
he
i
s
P
u
rs
ui
ng
P
h
.
D
.
d
e
gree
a
t
Hi
gh
V
oltag
e
i
n
F
a
cul
t
y
o
f
E
l
e
ct
rical
E
ngi
neerin
g,
U
THM
.
H
i
s
r
es
earc
h
i
nteres
t
i
n
clu
d
es
t
he
d
ynamic
a
rc
m
odelling
o
f
p
o
l
l
u
tio
n fl
ash
over
on
h
i
gh
vo
lt
ag
e
o
u
td
oo
r in
sulators
M
o
hd
Ai
zam
T
al
ib
r
eceiv
e
d
h
i
s
Bachel
or
i
n
El
e
c
t
r
ical
E
n
g
i
n
eeri
n
g
f
r
om
t
he
U
ni
vers
it
y
of
P
o
rts
m
o
u
t
h
,
UK
i
n
19
97
,
and
Mast
er
d
eg
re
e
in
E
l
e
ct
rical
E
n
g
i
n
ee
ring
f
rom
Uni
v
ersiti
Tenaga
N
a
sio
n
al
(
UNIT
E
N
)
,
M
a
lay
s
ia
i
n
2
0
0
1
.
U
pon
grad
uat
i
on
i
n
19
97
,
h
e
w
o
rked
w
ith
A
BB
T
r
ansmi
s
sion
a
nd
D
istribu
tion
S
d
n Bh
d
a
s
a
D
esi
gn
Eng
i
n
eer.
S
i
n
ce 1
998
, h
e
h
as
been
em
p
l
oyed
b
y
T
NB
R
esearch
S
dn
B
h
d
a
s
a
Research
E
n
g
i
n
eer.
His
res
earch
i
n
t
e
rests
are
in
t
ransf
o
rm
er
co
ndi
ti
on
m
o
n
itori
n
g
,
i
n
s
ul
a
tio
n
di
agn
o
s
tic
a
nd
d
iel
e
ct
ric
m
eas
u
r
em
en
ts
.
H
e
i
s
current
ly
a
P
h.D
.
d
e
gree
s
t
ud
ent
at
U
ni
versit
i T
e
kno
lo
gi
M
alay
sia.
Evaluation Warning : The document was created with Spire.PDF for Python.