I
nte
rna
t
io
na
l J
o
urna
l o
f
Adv
a
nces in Applie
d Science
s
(
I
J
AAS)
Vo
l.
10
,
No
.
3
,
Sep
tem
b
er
202
1
,
p
p
.
21
2
~
22
6
I
SS
N:
2
2
5
2
-
8
8
1
4
,
DOI
:
1
0
.
1
1
5
9
1
/ijaas.v
10
.
i
3
.
p
p
21
2
-
22
6
212
J
o
ur
na
l ho
m
ep
a
g
e
:
h
ttp
:
//ij
a
a
s
.
ia
esco
r
e.
co
m
Rev
iew of
p
ro
tec
t
io
n
a
spects o
f
mi
c
ro
g
rid devices
Ash
o
k
e
K
um
a
r
B
a
s
u
De
p
a
rtme
n
t
El
e
c
tri
c
a
l
En
g
i
n
e
e
rin
g
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T
h
e
Ne
o
ti
a
Un
i
v
e
rsity
,
In
d
ia
Art
icle
I
nfo
AB
S
T
RAC
T
A
r
ticle
his
to
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y:
R
ec
eiv
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Au
g
9
,
2
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R
ev
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r
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r
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A
m
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ri
d
is
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ired
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o
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li
a
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a
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n
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n
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t
d
e
m
a
n
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it
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it
h
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to
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o
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s
o
r
i
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g
r
id
-
c
o
n
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e
c
ted
m
o
d
e
s.
In
th
is
c
o
n
tex
t
,
it
is
m
o
st
imp
o
rtan
t
to
a
d
d
re
ss
a
c
o
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h
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siv
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e
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e
o
f
t
h
e
m
icro
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rid
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it
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g
b
o
t
h
th
e
m
o
d
e
s
o
f
o
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e
ra
ti
o
n
s.
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is
p
a
p
e
r
c
o
n
c
e
n
trate
s
o
n
th
e
im
p
a
c
ts
o
f
v
a
ri
o
u
s
d
e
v
ice
s,
li
k
e
d
istri
b
u
ted
e
n
e
r
g
y
re
so
u
rc
e
s
(
DERs
)
,
tran
sfo
rm
e
rs,
sw
it
c
h
e
s,
m
icro
g
rid
t
o
p
o
l
o
g
y
,
c
o
m
m
u
n
ica
ti
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t
y
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e
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g
ro
u
n
d
in
g
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y
p
e
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t
o
n
a
m
e
a
fe
w,
o
n
th
e
m
icro
g
rid
p
r
o
tec
ti
o
n
s
y
ste
m
s
.
Th
e
p
a
p
e
r
re
v
iew
e
s
p
re
v
io
u
s
wo
rk
s
fo
r
t
h
e
v
a
rio
u
s
a
s
p
e
c
ts,
li
k
e
c
h
a
ra
c
teristi
c
s,
c
o
n
stru
c
ti
o
n
,
o
f
th
e
se
d
e
v
ice
s
in
t
h
e
li
g
h
t
o
f
p
ro
tec
ti
o
n
.
T
h
is
re
v
iew
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wo
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k
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u
se
fu
l
fo
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t
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re
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a
rc
h
in
t
h
e
field
o
f
m
ic
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rid
p
ro
tec
ti
o
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a
s we
ll
a
s in
th
e
se
lec
ti
o
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o
f
i
ts d
e
v
ice
s.
K
ey
w
o
r
d
s
:
D
is
tr
ib
u
ted
en
er
g
y
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eso
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I
s
lan
d
ed
m
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e
Mic
r
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id
p
r
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tectio
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P
o
in
t o
f
co
m
m
o
n
c
o
u
p
lin
g
Po
wer
in
v
er
ter
T
h
is i
s
a
n
o
p
e
n
a
c
c
e
ss
a
rticle
u
n
d
e
r th
e
CC B
Y
-
SA
li
c
e
n
se
.
C
o
r
r
e
s
p
o
nd
ing
A
uth
o
r
:
Ash
o
k
e
Ku
m
ar
B
asu
Dep
ar
tm
en
E
lectr
ical
E
n
g
in
ee
r
in
g
Neo
tia
Un
iv
er
s
ity
2
0
/1
,
Kh
a
n
p
u
r
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o
ad
,
Ko
lk
ata
7
0
0
0
4
7
,
I
n
d
ia
E
m
ail:
ash
o
k
ek
u
m
a
r
b
asu
@
g
m
ail.
co
m
NO
M
E
N
CL
A
T
UR
E
DE
R
:
d
is
tr
ib
u
ted
en
er
g
y
r
eso
u
r
ce
s
DG
:
d
is
tr
ib
u
ted
g
en
er
at
o
r
/ g
e
n
er
atio
n
ES
:
en
er
g
y
s
to
r
a
g
e
C
-
DG
:
co
n
v
er
ter
-
b
ased
d
is
tr
ib
u
ted
g
en
e
r
ato
r
D
-
DG
:
d
ir
ec
tly
-
c
o
u
p
led
d
is
tr
i
b
u
ted
g
e
n
er
ato
r
PC
C
:
p
o
in
t o
f
co
m
m
o
n
co
u
p
lin
g
FR
E
E
DM
:
f
u
tu
r
e
r
en
ewa
b
le
elec
tr
ic
en
er
g
y
d
eliv
er
y
an
d
m
an
ag
em
en
t
T
HD:
to
tal
h
ar
m
o
n
ic
d
is
to
r
tio
n
1.
I
NT
RO
D
UCT
I
O
N
B
esid
es
m
an
y
d
ev
ices
o
f
a
m
i
cr
o
g
r
id
,
m
o
s
t
im
p
o
r
tan
t
a
r
e
D
E
R
s
(
wh
ich
in
clu
d
e
E
Ses
as
well
as
DGs
o
f
b
o
th
C
-
DG
an
d
D
-
DG
ty
p
e
s
)
,
tr
an
s
f
o
r
m
er
s
,
lin
es
an
d
d
if
f
er
en
t
lo
ad
s
.
A
m
icr
o
g
r
id
ca
n
b
e
an
in
d
e
p
en
d
e
n
t
AC
o
r
DC
n
etwo
r
k
s
o
r
a
c
o
m
b
in
atio
n
th
er
eo
f
.
AC
d
is
tr
ib
u
tio
n
n
etwo
r
k
s
m
a
y
b
e
o
f
in
d
iv
id
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al
o
r
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y
co
m
b
in
atio
n
o
f
s
in
g
le
-
o
r
th
r
e
e
-
p
h
ase,
lo
w
-
v
o
ltag
e
(
L
V)
o
r
m
ed
iu
m
-
v
o
ltag
e
(
MV
)
,
p
o
wer
f
r
eq
u
en
c
y
o
r
ev
e
n
a
h
ig
h
f
r
eq
u
en
cy
AC
(
HFAC
)
g
r
id
.
Mic
r
o
g
r
i
d
ca
n
f
lip
-
f
l
o
p
p
ar
tly
/f
u
lly
i
n
eith
er
o
f
n
o
r
m
a
l
(
g
r
id
-
c
o
n
n
ec
te
d
)
o
r
au
to
n
o
m
o
u
s
m
o
d
es.
T
h
e
Fi
g
u
r
e
.
1
r
ep
r
esen
ts
a
s
am
p
le
m
i
cr
o
g
r
id
,
wh
er
e
t
h
e
m
icr
o
g
r
id
i
s
a
co
m
b
in
atio
n
o
f
v
ar
io
u
s
zo
n
es
o
f
DC
,
AC
,
o
r
ev
en
a
HFAC
g
r
id
[
1
]
,
[
2
]
.
A
DC
m
icr
o
g
r
id
(
Z
o
n
e
I
)
is
a
d
is
tr
ib
u
tio
n
s
y
s
tem
co
m
p
r
is
in
g
o
f
DC
lo
ad
s
,
E
S
e
lem
en
ts
,
an
d
DG
r
eso
u
r
ce
s
o
f
DC
o
u
tp
u
t
v
o
ltag
es
lik
e
s
o
lar
PV,
f
u
el
ce
ll.
I
n
an
AC
m
icr
o
g
r
id
(
Z
o
n
e
I
I
)
,
L
V/
MV
AC
b
u
s
es
co
n
n
ec
t
AC
l
o
ad
s
to
AC
r
eso
u
r
ce
s
(
lik
e
m
icr
o
tu
r
b
i
n
e,
d
iesel
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t J Ad
v
Ap
p
l Sci
I
SS
N:
2
2
5
2
-
8
8
1
4
R
ev
iew
o
f p
r
o
tectio
n
a
s
p
ec
ts
o
f m
icro
g
r
id
d
ev
ices
(
A
s
h
o
ke
K
u
ma
r
B
a
s
u
)
213
g
en
er
ato
r
s
)
.
AC
b
u
s
es
ca
n
also
b
e
f
o
u
n
d
ap
p
licatio
n
with
DC
d
ev
ices
b
u
t
th
r
o
u
g
h
b
id
ir
ec
tio
n
al
co
n
v
e
r
ter
s
.
T
h
e
HFAC
m
icr
o
g
r
id
(
Z
o
n
e
I
I
I
)
r
eq
u
ir
es
u
n
iv
e
r
s
al
ac
tiv
e
p
o
wer
lin
e
co
n
d
itio
n
er
(
UPLC
)
to
in
ter
co
n
n
ec
t
to
th
e
L
V/MV
AC
b
u
s
es.
Ad
o
p
tio
n
o
f
th
is
s
y
s
tem
is
to
co
n
tr
o
l
ac
tiv
e
an
d
r
ea
ctiv
e
p
o
wer
f
lo
ws
in
eith
er
d
ir
ec
tio
n
o
f
th
e
m
icr
o
g
r
i
d
.
T
h
e
co
n
v
er
ter
s
u
s
ed
in
th
e
DC
m
icr
o
g
r
id
ar
e
o
f
th
e
DC
/AC
t
y
p
e
an
d
co
n
n
ec
t
th
e
DC
m
icr
o
g
r
id
to
th
e
L
V/MV
AC
b
u
s
es.
Dir
ec
t
co
n
n
ec
tio
n
o
f
r
en
ewa
b
le
-
DE
R
s
in
to
th
e
DC
b
u
s
es
h
as
two
p
o
s
itiv
e
ef
f
ec
ts
-
f
ir
s
tly
,
in
c
r
ea
s
e
th
e
o
v
e
r
all
ef
f
icien
c
y
o
f
t
h
e
n
etwo
r
k
,
d
u
e
t
o
r
e
d
u
ctio
n
in
t
h
e
n
u
m
b
er
o
f
co
n
v
er
ter
s
b
y
a
s
in
g
le
o
n
e
an
d
r
ed
u
cin
g
th
e
r
eq
u
ir
em
en
t
o
f
en
er
g
y
tr
an
s
f
o
r
m
in
g
as
DC
lo
ad
s
ar
e
s
u
p
p
lied
d
ir
ec
tly
,
an
d
s
ec
o
n
d
ly
,
in
c
r
ea
s
es
th
e
p
o
wer
q
u
ality
o
f
th
e
n
etwo
r
k
.
HFAC
s
y
s
tem
s
with
f
r
eq
u
en
cies
r
an
g
in
g
f
r
o
m
4
0
0
Hz
to
2
0
k
Hz
ar
e
cu
r
r
en
t
ly
u
n
d
er
tr
ial
f
o
r
p
o
we
r
d
is
tr
ib
u
tio
n
s
y
s
tem
s
.
T
h
e
HF
AC
s
y
s
tem
h
as,
i
n
g
en
er
al,
th
e
ad
v
an
tag
es
o
f
s
m
all
in
s
ize,
h
ig
h
e
r
p
o
wer
d
en
s
ity
,
an
d
m
o
d
u
lar
b
u
t
f
o
r
a
p
p
lic
atio
n
in
m
ic
r
o
g
r
i
d
s
ca
n
ca
u
s
e
h
i
g
h
p
o
wer
lo
s
s
es
an
d
v
o
ltag
e
d
r
o
p
s
al
o
n
g
th
e
li
n
e
[
3
]
,
[
4
]
.
As
p
er
r
ef
er
en
c
es
[
5
]
,
[
6
]
,
th
e
C
-
DG
m
icr
o
g
r
id
s
r
esp
o
n
d
s
s
lo
wly
a
n
d
E
S
is
n
ec
ess
ar
y
f
o
r
th
is
ty
p
e
o
f
m
icr
o
g
r
id
s
wh
er
e
lo
ad
s
ar
e
m
o
s
tly
s
en
s
itiv
e
an
d
p
o
wer
q
u
ality
is
co
n
ce
r
n
e
d
.
I
n
th
e
g
r
id
-
co
n
n
ec
ted
m
o
d
e,
E
S
m
a
y
e
n
s
u
r
e
l
o
ad
lev
elin
g
an
d
r
e
d
u
cin
g
th
e
p
o
wer
ex
ch
a
n
g
e
with
th
e
n
et
wo
r
k
wh
ich
m
ak
es
th
e
s
y
s
tem
o
p
er
atio
n
m
o
r
e
ef
f
icien
t
an
d
f
lex
ib
le.
E
S
m
ay
en
h
an
ce
DE
R
p
en
etr
atio
n
a
n
d
co
n
tr
i
b
u
te
t
o
b
etter
q
u
ality
o
f
en
er
g
y
d
eliv
er
y
t
o
c
u
s
to
m
er
s
.
A
co
m
p
o
s
ite
E
S
s
y
s
tem
is
p
r
o
p
o
s
ed
to
m
ee
t
t
h
e
co
n
tr
o
l
o
f
E
S
an
d
to
e
n
s
u
r
e
s
u
cc
ess
f
u
l
tr
an
s
itio
n
to
is
lan
d
ed
m
o
d
e
as
well.
T
h
is
co
m
p
o
s
ite
E
S
s
y
s
tem
co
n
tain
s
b
o
th
h
ig
h
en
e
r
g
y
d
e
n
s
ity
s
to
r
ag
e
b
atter
y
an
d
h
ig
h
-
p
o
wer
d
en
s
ity
s
to
r
a
g
e
u
ltra
ca
p
ac
ito
r
[
1
]
-
[
6]
.
I
n
th
e
Fig
u
r
e
1
,
t
h
e
d
ash
e
d
lin
es
in
d
icate
in
ter
co
n
n
ec
tio
n
o
f
‘
C
B
s
’
b
y
co
m
m
u
n
i
ca
tio
n
n
et
wo
r
k
.
T
h
e
s
y
m
b
o
l
‘
C
B
’
in
Fig
u
r
e
1
is
a
co
m
b
in
atio
n
o
f
v
ar
io
u
s
d
e
v
ices,
lik
e
cir
cu
it
b
r
ea
k
e
r
s
,
in
tellig
en
t
elec
tr
o
n
ic
d
ev
ices
(
I
E
Ds
)
,
r
ela
y
s
-
as
p
er
th
e
d
em
an
d
o
f
p
r
o
tectio
n
r
eq
u
ir
em
en
ts
.
Mic
r
o
g
r
id
ce
n
tr
al
co
n
tr
o
ller
(
MG
C
C
)
h
as
a
ce
n
tr
al
p
r
o
tectio
n
ce
n
ter
(
C
PC
)
u
n
it
in
s
id
e,
wh
ich
co
n
tr
o
l
ON/OFF
o
f
C
B
s
b
y
s
en
d
in
g
/r
ec
eiv
in
g
s
ig
n
als
o
v
er
th
e
co
m
m
u
n
icatio
n
n
etw
o
r
k
[
7
]
.
An
ap
p
r
o
p
r
iate
d
esig
n
in
g
o
f
m
icr
o
g
r
id
p
r
o
tectio
n
s
y
s
tem
is
m
ea
n
t
to
s
elec
t
its
p
r
o
p
er
d
ev
ices.
T
h
i
s
d
esig
n
f
ac
es
two
i
m
p
o
r
tan
t
p
r
o
b
lem
s
-
f
ir
s
tly
,
d
y
n
a
m
ic
n
atu
r
e
o
f
m
icr
o
g
r
i
d
,
ar
is
in
g
d
u
e
to
co
n
n
ec
tio
n
o
r
d
is
co
n
n
ec
tio
n
o
f
its
lo
ad
s
an
d
/o
r
DE
R
u
n
its
at
an
y
tim
e,
s
ec
o
n
d
ly
m
icr
o
g
r
id
s
o
p
er
atio
n
in
b
o
th
g
r
id
-
co
n
n
ec
ted
an
d
a
u
to
n
o
m
o
u
s
m
o
d
es
with
d
if
f
er
en
t
s
h
o
r
t
-
cir
c
u
itin
g
cu
r
r
en
ts
.
A
co
m
p
r
eh
e
n
s
iv
e
s
ch
em
e
s
h
o
u
ld
b
e
d
esig
n
e
d
to
p
r
o
tect
t
h
e
n
etwo
r
k
in
b
o
th
m
o
d
es.
Ag
ain
,
in
cr
ea
s
in
g
co
n
n
ec
tio
n
s
o
f
v
ar
io
u
s
ty
p
e
s
an
d
s
izes
o
f
DE
R
s
at
th
e
f
ee
d
er
s
in
th
e
d
is
tr
ib
u
tio
n
s
y
s
tem
s
h
av
e
laid
ch
allen
g
in
g
d
e
m
an
d
s
o
n
f
ee
d
er
p
r
o
tectio
n
s
.
DGs
h
av
e
d
if
f
er
en
t
ty
p
es
an
d
ch
a
r
ac
ter
is
tics
.
E
ac
h
ty
p
e
h
as
d
if
f
er
en
t
p
r
o
tectio
n
asp
ec
ts
o
f
s
h
o
r
t
cir
cu
it
cu
r
r
e
n
t
an
d
c
o
o
r
d
in
atio
n
.
Switch
es
(
in
clu
d
in
g
PC
C
)
,
tr
an
s
f
o
r
m
er
s
,
f
ee
d
er
s
h
av
e
d
if
f
er
e
n
t
ty
p
es
as
p
er
th
eir
u
s
ag
es
an
d
ea
ch
ty
p
e
h
as
r
o
le
o
n
p
r
o
tectio
n
.
T
o
p
o
lo
g
y
i
s
o
n
e
o
f
th
e
m
o
s
t
im
p
o
r
tan
t
f
ac
t
o
r
s
o
n
w
h
ich
p
r
o
tectio
n
s
tr
ateg
ies
o
f
m
i
cr
o
g
r
id
d
e
p
en
d
s
.
T
h
e
m
icr
o
g
r
id
s
p
an
s
,
u
s
u
ally
,
a
s
m
all
ar
ea
an
d
th
e
co
m
m
u
n
ica
tio
n
s
y
s
tem
is
,
g
en
er
ally
,
u
s
ed
eith
er
o
f
p
ilo
t
wir
es
ty
p
es
o
r
o
p
tical
f
ib
e
r
s
ty
p
es
o
r
th
e
E
t
h
er
n
et
ty
p
es.
C
o
m
m
u
n
icatio
n
s
y
s
tem
is
th
e
b
ac
k
b
o
n
e
o
f
th
e
m
icr
o
g
r
id
p
r
o
tec
tio
n
.
Fau
lt
cu
r
r
en
t
lim
iter
(
FC
L
)
an
d
g
r
o
u
n
d
in
g
s
y
s
tem
h
av
e
also
b
ee
n
tak
en
in
to
co
n
s
id
er
atio
n
d
u
e
t
o
th
eir
u
s
ag
e
in
p
r
o
tectio
n
f
u
n
ctio
n
[
7
],
[
8]
.
Fig
u
r
e
1
.
Sam
p
le
m
icr
o
g
r
id
: Co
m
p
o
s
ite
s
tr
u
ct
u
r
e
with
DC
-
,
AC
-
an
d
HFAC
-
s
y
s
tem
s
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
2
5
2
-
8
8
1
4
I
n
t J Ad
v
Ap
p
l Sci
,
Vo
l.
10
,
No
.
3
,
Sep
tem
b
er
2
0
2
1
:
21
2
–
22
6
214
I
n
th
e
p
r
esen
t
p
a
p
er
th
e
a
u
th
o
r
h
as
f
o
cu
s
ed
,
m
ai
n
ly
,
o
n
t
h
e
p
r
o
tectio
n
asp
ec
ts
o
f
t
h
e
co
n
s
titu
en
t
d
ev
ices
o
f
m
icr
o
g
r
i
d
s
an
d
r
e
v
iewe
d
r
esear
ch
er
s
’
wo
r
k
s
to
ca
s
t
lig
h
t
o
n
th
is
to
p
ic.
T
h
e
p
r
esen
t
s
u
r
v
ey
is
o
r
g
an
ized
in
t
o
t
h
r
ee
s
ec
tio
n
s
.
Fo
llo
win
g
th
e
s
ec
tio
n
1
o
n
in
tr
o
d
u
ctio
n
,
s
ec
tio
n
2
is
d
iv
id
ed
in
to
s
ev
en
s
u
b
-
s
ec
tio
n
s
r
esp
ec
tiv
ely
o
n
“DE
R
s
an
d
p
o
wer
in
v
er
ter
s
”,
“Po
in
t
o
f
co
m
m
o
n
co
u
p
lin
g
(
PC
C
)
”,
“T
r
an
s
f
o
r
m
er
s
”,
“f
ee
d
er
s
/b
r
an
c
h
es
an
d
to
p
o
lo
g
y
”,
“switch
es
-
cir
cu
it
b
r
ea
k
er
s
,
r
ec
lo
s
er
s
,
s
ec
tio
n
alis
er
s
an
d
f
u
s
es”,
“c
o
m
m
u
n
icatio
n
d
e
v
ices”,
an
d
“o
th
er
d
ev
ices”.
E
ac
h
s
u
b
-
s
ec
tio
n
is
,
ag
ain
,
d
iv
id
ed
a
s
p
er
r
elev
a
n
ce
to
m
icr
o
g
r
id
p
r
o
tectio
n
.
Sectio
n
3
d
r
aws “
co
n
clu
s
io
n
”.
L
astl
y
,
ac
k
n
o
wled
g
e
m
en
t a
n
d
r
ef
er
e
n
ce
s
ar
e
in
clu
d
ed
.
2.
DE
VI
CE
S
A
ND
P
RO
T
E
C
T
I
O
NAL A
SPEC
T
S
Mic
r
o
g
r
id
s
ar
e
co
m
p
o
s
ed
o
f
b
o
th
m
ain
/ess
en
tial
d
ev
ices
f
o
r
g
r
id
f
o
r
m
atio
n
,
lik
e
DE
R
s
,
tr
an
s
f
o
r
m
er
s
,
lin
es,
lo
a
d
s
an
d
o
th
er
a
u
x
iliar
y
/d
esira
b
le
c
o
m
p
o
n
en
ts
,
lik
e
p
r
o
tectiv
e
d
ev
ic
es,
co
n
tr
o
ller
s
.
T
h
e
au
x
iliar
y
/d
esira
b
le
co
m
p
o
n
e
n
t
s
ar
e
u
s
ed
f
o
r
f
au
lt f
r
ee
r
u
n
n
in
g
o
f
ea
ch
ess
en
tial d
ev
ice,
as a
wh
o
le,
th
e
o
v
er
all
m
icr
o
g
r
id
,
s
o
th
at
th
e
cu
s
to
m
er
s
ar
e
s
u
p
p
lied
with
u
n
in
ter
r
u
p
ted
q
u
ality
o
f
p
o
wer
.
E
ac
h
o
f
th
ese
ess
en
tial
d
ev
ices
o
f
m
icr
o
g
r
id
s
h
as
v
ar
io
u
s
co
n
s
tr
u
ctio
n
a
n
d
ch
ar
ac
ter
is
tics
f
ea
tu
r
es,
wh
ich
h
a
v
e
im
p
ac
ts
o
n
t
h
e
m
icr
o
g
r
id
p
r
o
tectio
n
.
T
h
e
p
r
es
en
t
au
th
o
r
h
as
r
ev
iewe
d
th
e
r
e
s
ea
r
ch
er
s
’
wo
r
k
s
to
f
o
cu
s
o
n
t
h
ese
d
ev
ices
in
th
e
lig
h
t o
f
m
icr
o
g
r
id
p
r
o
tectio
n
.
2
.
1
.
DE
Rs
a
n
d
p
o
wer
inv
er
t
er
s
Mo
s
t
im
p
o
r
tan
t
co
m
p
o
n
en
t
o
f
a
m
icr
o
g
r
id
is
its
DE
R
s
,
wh
ich
in
clu
d
e
b
o
th
DGs
an
d
E
Ses
.
Po
wer
in
v
er
ter
s
ar
e
u
s
ed
to
co
n
n
ec
t
DGs
an
d
E
Ses
to
th
e
m
icr
o
g
r
id
b
u
s
.
E
ac
h
s
u
ch
d
ev
ice
is
r
ev
iewe
d
s
ep
ar
ately
in
th
e
f
o
llo
win
g
s
u
b
-
s
ec
tio
n
s
.
2
.
1
.
1
.
DG
s
I
n
a
m
icr
o
g
r
id
,
DGs
ca
n
b
e
class
if
ied
as
co
n
v
er
ter
-
b
ased
(
C
-
DGs)
an
d
d
ir
ec
tly
-
c
o
u
p
le
d
(
D
-
DGs).
Sy
n
ch
r
o
n
o
u
s
an
d
asy
n
ch
r
o
n
o
u
s
g
en
er
ato
r
s
ar
e
D
-
DGs
an
d
t
h
ey
ar
e
co
u
p
led
to
th
e
r
o
tatin
g
m
ac
h
in
es,
s
u
ch
as
d
iesel
en
g
in
es,
m
icr
o
tu
r
b
i
n
es,
an
d
win
d
tu
r
b
in
es.
W
h
er
ea
s
C
-
DGs
ar
e
b
o
th
s
tati
c
m
ac
h
in
es
lik
e
s
o
lar
PV
m
o
d
u
les,
Fu
el
ce
lls
an
d
r
o
tati
n
g
m
ac
h
i
n
es
lik
e
win
d
tu
r
b
in
e
s
,
m
icr
o
tu
r
b
i
n
es
[
4
]
.
T
h
e
C
-
D
Gs
ar
e
o
f
two
ty
p
es
cu
r
r
en
t
-
c
o
n
tr
o
lled
a
n
d
v
o
ltag
e
-
co
n
tr
o
lled
.
T
h
e
am
o
u
n
t o
f
f
a
u
lt c
u
r
r
en
t su
p
p
lied
b
y
th
ese
DGs d
u
r
in
g
a
f
au
lt is
m
o
s
t
im
p
o
r
ta
n
t
co
n
s
id
er
atio
n
in
m
icr
o
g
r
id
p
r
o
tectio
n
s
tr
ateg
y
[
9
]
.
Sh
o
r
t
cir
c
u
it
ch
ar
ac
te
r
is
tics
v
ar
y
with
th
e
ty
p
es
o
f
DGs.
D
-
DGs
ar
e
ch
a
r
ac
ter
ized
b
y
h
ig
h
s
h
o
r
t
-
cir
cu
i
t
cu
r
r
e
n
t
co
n
tr
ib
u
tio
n
t
h
at
m
a
y
r
ea
c
h
1
0
p
er
u
n
it
(
p
.
u
.
)
o
f
th
eir
r
esp
ec
tiv
e
r
at
ed
cu
r
r
en
t
a
n
d
th
is
cu
r
r
en
t
d
ep
en
d
s
o
n
th
e
r
ea
ctan
ce
o
f
th
e
g
en
er
ato
r
a
n
d
co
n
n
ec
tin
g
t
r
an
s
f
o
r
m
e
r
.
W
h
er
ea
s
,
C
-
DGs
h
av
e
lim
ited
co
n
tr
ib
u
tio
n
to
s
h
o
r
t
-
cir
cu
it
cu
r
r
en
t
s
o
f
u
p
to
4
p
.
u
.
o
f
th
e
r
ated
cu
r
r
en
t.
Asy
n
ch
r
o
n
o
u
s
g
en
er
ato
r
s
d
o
n
o
t
h
a
v
e
th
e
ir
in
d
ep
en
d
en
t
ex
citatio
n
s
y
s
t
em
s
.
So
,
th
er
e
is
a
r
ap
id
d
ec
ay
o
f
th
eir
f
au
lt
c
u
r
r
en
ts
b
elo
w
th
e
r
ated
cu
r
r
en
t
an
d
it
p
o
s
es
d
if
f
ic
u
lty
f
o
r
a
r
elay
to
p
ick
u
p
th
e
f
au
lt
[
1
0
]
,
[
1
1
]
.
A
c
r
o
wb
ar
-
r
esis
to
r
s
y
s
tem
is
co
m
m
o
n
ly
u
s
ed
to
p
r
o
tect
th
e
r
o
to
r
cir
cu
it
o
f
d
o
u
b
ly
-
f
e
d
in
d
u
ctio
n
g
en
e
r
ato
r
s
(
DF
I
G)
an
d
p
o
wer
c
o
n
v
e
r
ter
s
f
r
o
m
o
v
er
v
o
ltag
e
an
d
th
er
m
al
b
r
ea
k
d
o
wn
u
n
d
e
r
f
a
u
lty
s
itu
atio
n
s
an
d
th
ese
DFI
Gs
b
e
h
av
e
lik
e
th
e
co
n
v
en
tio
n
al
asy
n
ch
r
o
n
o
u
s
g
en
e
r
ato
r
s
,
with
a
lar
g
e
in
itial
cu
r
r
en
t
th
at
q
u
ick
ly
d
ec
ay
s
[
1
1
]
-
[
1
3
]
.
B
o
th
s
y
n
ch
r
o
n
o
u
s
an
d
asy
n
ch
r
o
n
o
u
s
DGs
r
ed
u
ce
o
p
e
r
atio
n
tim
e
o
f
o
v
er
cu
r
r
en
t
r
ela
y
s
,
b
u
t
th
e
im
p
a
ct
o
f
asy
n
ch
r
o
n
o
u
s
DGs,
as
n
o
n
-
s
y
n
ch
r
o
n
izatio
n
ty
p
e,
o
u
tweig
h
s
th
e
s
y
n
ch
r
o
n
o
u
s
DGs.
Sy
n
ch
r
o
n
o
u
s
o
r
asy
n
ch
r
o
n
o
u
s
-
b
ased
DGs
h
av
e
an
u
n
c
o
n
tr
o
lled
cu
r
r
en
t
o
u
tp
u
t
d
u
r
in
g
f
au
lts
wh
er
ea
s
C
-
DGs
h
av
e
cu
r
r
en
t
o
u
tp
u
t
d
e
p
e
n
d
en
t
o
n
th
eir
co
n
tr
o
l
m
eth
o
d
r
ath
er
th
an
th
e
ty
p
e
o
f
th
e
g
en
er
ato
r
f
o
r
in
s
tan
ce
,
PV sy
s
tem
is
d
ep
en
d
en
t o
n
m
ax
im
u
m
p
o
wer
-
p
o
in
t tr
ac
k
e
r
(
MPPT)
[
1
]
,
[
4
]
,
[
9
]
,
[
14
]
,
[
1
5
]
.
T
h
er
e
ar
e
u
s
u
ally
two
co
n
tr
o
l
s
ch
em
es
o
f
C
-
DG
u
n
it’s
d
–
q
co
n
tr
o
l
an
d
a
-
b
-
c
co
n
tr
o
l.
I
n
th
e
a
-
b
-
c
co
n
tr
o
l
ea
ch
p
h
ase
is
c
o
n
tr
o
ll
ed
s
ep
ar
ately
,
b
u
t
n
o
t
in
th
e
c
ase
f
o
r
d
–
q
co
n
tr
o
l.
W
h
en
f
au
lt
is
o
cc
u
r
r
e
d
in
o
n
e
p
h
ase,
co
n
tr
o
l
lo
o
p
lim
its
cu
r
r
en
t
o
f
all
p
h
ases
(
b
o
th
h
ea
lth
y
an
d
f
au
lty
)
in
d
–
q
co
n
t
r
o
l,
b
u
t
th
e
cu
r
r
en
ts
o
f
h
ea
lth
y
p
h
ases
will
r
em
ain
co
n
s
tan
t
in
a
-
b
-
c
c
o
n
tr
o
l.
T
h
is
h
elp
s
th
e
o
v
er
cu
r
r
en
t
r
elay
to
s
en
s
e
an
d
s
u
b
s
eq
u
en
tly
,
clea
r
th
e
f
au
lt
in
a
-
b
-
c
co
n
tr
o
l.
T
h
u
s
,
th
e
au
t
h
o
r
s
o
f
r
ef
s
[
4
]
an
d
[
1
6
]
s
u
g
g
est
d
o
u
b
le
co
n
tr
o
l
s
tr
ateg
y
d
–
q
co
n
tr
o
l
in
n
o
r
m
a
l
m
o
d
e
an
d
a
-
b
-
c
co
n
tr
o
l
i
n
f
a
u
lty
s
itu
atio
n
s
.
Ag
ain
,
v
o
ltag
e
-
co
n
tr
o
lled
C
-
DGs
s
h
o
w
a
d
if
f
er
e
n
t
f
au
lt
ch
ar
ac
t
er
is
tic
f
r
o
m
th
at
o
f
cu
r
r
en
t
-
co
n
tr
o
lled
o
n
e.
T
h
e
v
o
ltag
e
-
co
n
tr
o
lled
C
-
DGs
ar
e
u
n
ab
le
to
p
r
ec
is
ely
r
eg
u
late
th
eir
o
u
tp
u
t c
u
r
r
en
t a
n
d
ar
e
s
u
s
ce
p
tib
le
to
s
h
o
r
t c
ir
cu
it wh
e
r
ea
s
cu
r
r
en
t
-
co
n
tr
o
lled
o
n
es h
av
e
in
a
b
ilit
y
to
m
ain
tai
n
th
eir
ter
m
in
al
v
o
ltag
e
a
n
d
ar
e
v
u
ln
er
a
b
le
to
u
n
d
er
-
v
o
ltag
e
f
au
lts
[
4
]
,
[
5
]
,
[
16]
.
T
h
e
co
o
r
d
i
n
atio
n
is
an
o
th
er
i
m
p
o
r
tan
t
asp
ec
t
o
f
m
ico
g
r
id
p
r
o
tectio
n
wh
er
e
DE
R
s
h
av
e
an
im
p
o
r
tan
t
r
o
le.
Fo
r
an
y
g
iv
e
n
m
icr
o
g
r
i
d
n
etwo
r
k
,
s
ev
er
al
asp
ec
ts
,
s
u
ch
as
o
p
tim
u
m
lo
ca
tio
n
s
,
s
i
ze
s
,
m
ax
im
u
m
DG
p
en
etr
atio
n
lev
els,
p
lay
r
o
le
f
o
r
lo
s
s
o
f
p
r
o
tectio
n
co
o
r
d
i
n
atio
n
[
1
7
]
-
[
1
9
]
.
Fo
r
n
o
n
-
v
io
latio
n
o
f
p
r
o
tectio
n
co
o
r
d
in
atio
n
,
th
e
r
esear
ch
er
s
h
av
e
p
r
o
p
o
s
ed
v
ar
io
u
s
way
s
,
s
u
ch
as
:
i)
to
ad
ju
s
t
th
e
d
is
tan
ce
b
etwe
en
th
e
cu
r
v
es
o
f
o
v
e
r
cu
r
r
e
n
t
r
elay
s
in
o
p
er
atio
n
f
o
r
ad
d
i
n
g
o
f
D
G
u
n
its
,
ii)
f
o
r
f
in
d
in
g
o
p
tim
al
lo
ca
tio
n
o
f
a
DG
u
n
it,
an
d
iii)
th
e
m
ax
im
u
m
ca
p
ac
ity
o
f
a
DG
u
n
it
[
2
0
]
,
[
2
1
]
.
An
i
n
d
ex
is
d
ef
i
n
ed
a
n
d
ac
co
r
d
in
g
to
t
h
is
in
d
ex
,
ad
d
s
DG
r
eso
u
r
ce
s
to
th
e
m
icr
o
g
r
id
as lo
n
g
as it d
o
es n
o
t a
f
f
ec
t c
o
o
r
d
in
atio
n
o
f
o
v
e
r
cu
r
r
e
n
t r
elay
s
[
1
7
]
-
[
2
2
]
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t J Ad
v
Ap
p
l Sci
I
SS
N:
2
2
5
2
-
8
8
1
4
R
ev
iew
o
f p
r
o
tectio
n
a
s
p
ec
ts
o
f m
icro
g
r
id
d
ev
ices
(
A
s
h
o
ke
K
u
ma
r
B
a
s
u
)
215
Dy
n
am
ic
p
er
f
o
r
m
an
ce
o
f
a
m
icr
o
g
r
id
is
a
m
ajo
r
to
p
ic
in
p
r
o
tectio
n
.
Du
r
in
g
a
f
a
u
lt,
th
e
g
en
er
atin
g
u
n
its
m
u
s
t
s
u
p
p
ly
s
u
f
f
icie
n
t
s
h
o
r
t
-
cir
cu
it
cu
r
r
en
t
to
e
n
s
u
r
e
co
r
r
ec
t
co
o
r
d
in
ate
d
o
p
er
atio
n
o
f
th
e
p
r
o
tectio
n
d
ev
ices.
Ag
ain
,
f
o
llo
win
g
f
au
l
t
clea
r
an
ce
,
th
e
DGs
s
h
o
u
ld
r
e
co
v
er
a
n
d
s
u
p
p
ly
ac
tiv
e
p
o
wer
as
f
ast
as
p
o
s
s
ib
le
with
o
u
t
u
n
d
u
e
o
s
cilla
tio
n
s
,
an
d
f
u
r
th
er
to
s
u
p
p
o
r
t
q
u
ick
v
o
lt
ag
e
r
ec
o
v
er
y
,
th
e
DGs
r
eq
u
ir
e
s
to
s
u
p
p
ly
r
ea
ctiv
e
p
o
wer
,
o
r
to
r
e
d
u
ce
r
ea
ctiv
e
p
o
wer
co
n
s
u
m
p
tio
n
.
DG
m
an
u
f
ac
tu
r
e
r
s
in
tr
o
d
u
ce
d
th
e
c
o
n
tr
o
l
tech
n
iq
u
es
to
m
ee
t
th
e
ac
tiv
e
-
r
ea
ctiv
e
r
eq
u
ir
em
en
ts
.
Ho
wev
er
,
th
e
co
n
t
r
o
l
tech
n
iq
u
es
h
av
e
im
p
ac
t
o
n
th
e
s
h
o
r
t
cir
cu
it
b
eh
av
io
r
o
f
th
e
v
ar
io
u
s
ty
p
e
s
o
f
DGs
[
2
3
]
,
[
2
4
]
.
T
h
e
co
n
tr
o
l
tech
n
iq
u
es
ar
e
n
o
t
s
tan
d
ar
d
ized
an
d
h
a
v
e
in
tr
o
d
u
ce
d
u
n
ce
r
tain
ty
in
th
e
f
au
lt
cu
r
r
en
t
c
o
n
tr
ib
u
ti
o
n
o
f
t
h
e
DGs
-
it
is
a
p
p
ar
en
t
th
at
i
n
teg
r
atio
n
o
f
DGs
r
eq
u
i
r
es
p
r
o
tectio
n
th
at
is
ca
p
ab
le
o
f
m
ain
tain
i
n
g
p
r
o
tecti
o
n
co
o
r
d
i
n
atio
n
u
n
d
e
r
b
i
-
d
ir
e
ctio
n
al
an
d
v
ar
ia
b
le
p
o
wer
f
lo
w
c
o
n
d
itio
n
s
.
T
h
e
p
r
o
tectio
n
m
u
s
t
also
o
p
er
ate
co
r
r
ec
tly
u
n
d
er
th
e
co
n
d
itio
n
s
o
f
u
n
p
r
e
d
ictab
le
f
a
u
lt
cu
r
r
en
ts
[
1
1
]
,
[
13
]
,
[
25
]
,
[
2
6
]
.
No
n
-
r
o
tat
in
g
DG
p
e
n
etr
atio
n
,
esp
ec
ially
o
f
PV,
h
as
th
e
ef
f
ec
t
o
f
r
ed
u
ctio
n
o
f
th
e
ef
f
ec
tiv
e
s
y
s
tem
in
er
tia
le
ad
in
g
to
r
ed
u
ce
d
d
y
n
am
ic
p
er
f
o
r
m
an
ce
o
f
m
icr
o
g
r
i
d
[
1
1
]
,
[
2
7
]
.
B
alan
cin
g
f
au
lt
cu
r
r
en
t
f
o
r
all
p
o
s
s
ib
le
s
itu
ati
o
n
s
o
f
m
icr
o
g
r
id
is
co
m
p
licat
ed
an
d
h
ig
h
ly
ex
p
e
n
s
iv
e
[
4
]
,
[
2
8
]
.
T
h
e
r
e
ar
e
g
r
i
d
co
d
es
f
o
r
o
p
er
atio
n
o
f
DGs,
n
am
ely
,
-
i)
t
h
e
th
r
esh
o
l
d
v
o
lta
g
e
-
ab
o
v
e
wh
i
ch
th
e
DG
to
r
e
m
ain
co
n
n
ec
ted
,
ii
)
th
e
m
ax
im
u
m
cu
r
r
en
t
ca
p
ab
ili
ty
o
f
th
e
in
v
er
ter
-
b
ased
DG,
iii)
p
r
o
v
is
io
n
o
f
th
e
m
a
x
im
u
m
r
ea
ctiv
e
cu
r
r
en
t
o
f
th
e
DG
f
o
r
v
o
ltag
es
b
elo
w
0
.
5
p
u
[
1
4
]
.
As
p
er
th
e
n
ew
g
r
i
d
co
d
es
th
e
DGs
co
n
tin
u
e
c
o
n
n
ec
ted
f
o
r
a
s
h
o
r
t
d
u
r
atio
n
u
n
d
er
f
au
lt
c
o
n
d
itio
n
s
.
I
t
d
em
a
n
d
s
an
ti
-
is
lan
d
in
g
p
r
o
tectio
n
a
n
d
f
au
lt
r
i
d
e
th
r
o
u
g
h
(
FR
T
)
ca
p
a
b
ilit
y
to
b
e
co
n
s
id
er
ed
with
DG
u
n
it
.
E
Ses
an
d
p
h
o
to
v
o
lt
aic
(
PV)
s
y
s
tem
s
,
d
u
e
to
th
eir
l
o
w
f
au
lt r
id
e
th
r
o
u
g
h
(
FR
T
)
ca
p
ab
ilit
ies,
f
ac
e
d
if
f
icu
lties
t
o
clea
r
all
s
h
u
n
t a
n
d
h
ig
h
im
p
ed
an
ce
f
au
lts
(
HI
Fs
)
in
r
ad
ial
an
d
m
esh
s
tr
u
ctu
r
es.
An
d
ac
co
r
d
i
n
g
ly
,
v
a
r
iety
o
f
l
o
w
v
o
ltag
e
r
id
e
th
r
o
u
g
h
(
L
V
R
T
)
s
tan
d
ar
d
s
h
as
b
ee
n
f
r
am
ed
b
y
th
e
tech
n
ical
co
m
m
u
n
ity
[
2
9
]
-
[
3
4
]
.
2
.
1
.
2
.
E
S
s
y
s
t
em
s
T
h
er
e
ar
e
u
s
ag
es
o
f
en
er
g
y
s
to
r
ag
e
(
E
S)
d
ev
ices
in
m
icr
o
g
r
id
s
-
b
atter
y
,
u
ltra
ca
p
ac
ito
r
,
f
l
y
wh
ee
l,
to
n
am
e
a
f
ew.
I
n
g
en
e
r
al,
en
er
g
y
s
to
r
ag
e
wo
u
ld
b
e
co
n
n
ec
t
ed
to
th
e
m
icr
o
g
r
i
d
th
r
o
u
g
h
a
n
in
v
er
ter
in
te
r
f
ac
e
.
ES
e
s
im
p
r
o
v
e
p
o
wer
q
u
ality
v
ia
f
r
eq
u
en
c
y
r
eg
u
latio
n
[
2
9
]
.
T
h
ey
ar
e
b
en
ef
iciar
y
f
o
r
m
i
cr
o
g
r
id
o
w
n
er
s
in
m
an
y
way
s
:
i)
to
g
en
er
ate
m
o
s
t
ef
f
icien
t
an
d
least
ex
p
e
n
s
iv
e
p
o
wer
,
ii)
t
o
p
r
o
v
id
e
u
n
i
n
ter
r
u
p
te
d
p
o
wer
to
cr
itical
lo
ad
s
,
an
d
to
s
u
p
p
ly
t
h
e
em
er
g
e
n
cy
p
o
wer
d
u
r
in
g
s
to
r
m
s
,
eq
u
ip
m
en
t
f
ailu
r
es,
o
r
o
th
er
f
o
u
ls
,
iii)
to
en
s
u
r
e
s
ea
m
less
tr
an
s
f
er
to
th
e
is
lan
d
ed
m
o
d
e,
an
d
iv
)
to
e
n
h
an
ce
f
lex
ib
ilit
y
in
p
o
wer
g
en
er
atio
n
,
d
eliv
er
y
,
an
d
co
n
s
u
m
p
tio
n
[
6
]
,
[
3
5
]
.
L
ar
g
e
-
s
ca
le
in
teg
r
atio
n
o
f
E
Ses
in
cr
ea
s
es
th
e
ef
f
icien
cy
o
f
m
ain
g
r
id
s
-
in
tu
r
n
,
r
ed
u
ce
s
o
p
e
r
atio
n
co
s
t a
n
d
em
is
s
io
n
s
an
d
also
,
in
cr
ea
s
es p
o
wer
r
eliab
ilit
y
[
6
]
.
E
Ses
,
p
r
ef
er
en
tially
b
atter
ies,
is
co
n
n
ec
ted
to
th
e
m
icr
o
g
r
i
d
to
allo
w
th
e
u
s
e
o
f
co
n
v
en
t
io
n
al
o
v
er
-
cu
r
r
en
t
p
r
o
tectio
n
d
e
v
ices
[
3
6
]
-
[
3
8
]
.
T
h
e
b
atter
y
o
p
er
atio
n
is
lim
ited
b
y
th
e
f
au
lt
cu
r
r
en
t.
T
o
av
o
id
th
eir
d
am
ag
e,
its
o
p
er
atio
n
is
s
to
p
p
ed
in
s
tan
tly
wh
e
n
f
a
u
lt
cu
r
r
en
t
ex
ce
ed
s
an
ac
ce
p
tab
le
th
r
esh
o
ld
cu
r
r
en
t.
T
h
ese
d
ev
ices
h
av
e
th
e
d
is
ad
v
an
tag
e
o
f
h
ig
h
co
s
t.
T
h
e
f
au
lt
cu
r
r
en
t
am
p
litu
d
e
o
f
ca
p
ac
ito
r
-
E
S
is
v
er
y
h
ig
h
with
a
s
h
o
r
t
tim
e
co
n
s
tan
t
an
d
th
e
f
a
u
lt
cu
r
r
en
t
a
m
p
litu
d
e
d
ep
en
d
s
o
n
th
e
ca
p
ac
ity
o
f
th
e
ca
p
ac
ito
r
s
.
Fly
wh
ee
ls
an
d
b
atter
ies
-
E
Ses
ca
n
b
e
u
s
ed
t
o
p
r
o
v
id
e
s
u
p
p
lem
e
n
tar
y
s
h
o
r
t
-
cir
cu
it
lev
el
t
o
th
e
n
etwo
r
k
[
1
2
]
,
[
3
9
]
,
[
4
0
]
.
Fly
wh
ee
l
E
S
is
co
u
p
led
to
in
v
er
ter
-
in
ter
f
ac
ed
DG
to
s
u
p
p
ly
a
s
ig
n
if
ican
t
cu
r
r
e
n
t.
Fly
wh
ee
l
E
S
is
v
er
y
u
s
ef
u
l
f
o
r
cr
itical
lo
ad
,
esp
ec
ially
w
h
en
co
u
p
led
with
d
is
p
atch
a
b
le
DG
s
u
ch
as
d
iesel
g
en
er
ato
r
s
.
As
f
ly
wh
ee
ls
ar
e
ex
p
en
s
iv
e
an
d
r
eq
u
ir
e
a
s
o
p
h
is
ticated
co
n
tr
o
l
s
ch
em
e
f
o
r
c
o
o
r
d
in
atio
n
with
DG
in
a
m
i
cr
o
g
r
id
-
n
o
t
ev
er
y
in
v
er
ter
-
in
ter
f
ac
ed
DG
u
n
it is
eq
u
ip
p
e
d
with
a
f
ly
wh
ee
l sy
s
t
em
[
4
1
]
,
[
4
2
]
.
2
.
1
.
3
.
P
o
wer
inv
er
t
er
s
Po
wer
in
v
er
ter
s
,
b
r
o
ad
l
y
co
n
v
er
ter
s
,
h
av
e
m
an
y
f
u
n
ctio
n
s
to
s
er
v
e,
wh
en
is
u
s
ed
in
th
e
m
icr
o
g
r
id
,
m
ain
ly
,
to
c
o
n
tr
o
l
p
o
wer
f
lo
w
s
o
f
DE
R
s
,
to
s
tab
ilize
v
o
ltag
e
an
d
f
r
eq
u
e
n
cy
o
f
th
e
m
icr
o
g
r
id
,
an
d
to
co
n
v
er
t
th
e
o
p
er
atin
g
v
o
ltag
e
f
r
o
m
D
C
in
to
AC
an
d
v
ice
-
v
er
s
a
[
1
2
]
,
[
43
]
,
[
4
4
]
.
T
h
er
e
ar
e
two
m
o
d
es
o
f
co
n
tr
o
l
o
f
DC
/A
C
in
v
er
ter
:
i)
V
-
f
m
o
d
e
d
u
r
in
g
th
e
au
to
n
o
m
o
u
s
o
p
er
a
tio
n
to
s
tab
ilize
th
e
m
icr
o
g
r
id
v
o
ltag
e
an
d
f
r
eq
u
e
n
cy
an
d
ii)
P
-
Q
m
o
d
e
d
u
r
in
g
t
h
e
g
r
id
-
co
n
n
ec
ted
o
p
er
atio
n
.
T
h
e
latter
m
o
d
e
ad
ju
s
ts
th
e
in
jectio
n
o
f
ac
tiv
e
an
d
r
ea
ctiv
e
p
o
wer
f
lo
ws
in
to
th
e
m
ain
g
r
id
.
Mo
s
t
o
f
th
e
p
o
wer
in
v
er
ter
s
r
eq
u
ir
e
to
h
av
e
th
e
ca
p
ab
il
ity
to
lim
it
f
au
lt
cu
r
r
en
ts
to
av
o
id
th
eir
u
n
d
esira
b
le
d
am
ag
e
an
d
d
ig
ital
r
elay
s
ar
e
an
ef
f
ec
tiv
e
p
r
o
tectio
n
s
o
l
u
tio
n
f
o
r
t
h
e
DC
/AC
in
v
er
ter
s
[
1
2
]
,
[
3
6
]
.
Fo
r
p
r
o
tectio
n
f
r
o
m
th
e
f
au
lts
o
f
p
o
wer
in
v
er
ter
s
,
th
e
d
ev
ices,
lik
e
f
u
s
es,
no
-
f
u
s
e
cir
cu
it
b
r
ea
k
e
r
s
,
an
d
p
r
o
tectiv
e
r
elay
s
in
ad
d
itio
n
t
o
p
o
wer
-
s
em
ico
n
d
u
ct
o
r
s
witch
es
ar
e
u
s
ed
at
th
e
AC
s
id
e.
Dif
f
er
en
t
ty
p
es
o
f
p
o
wer
s
em
ico
n
d
u
cto
r
s
witch
es
h
av
e
d
if
f
er
en
t
ch
ar
ac
ter
is
tics
a
n
d
r
eq
u
ir
e
d
if
f
er
en
t
p
r
o
tectio
n
s
ch
em
es.
T
h
e
I
GB
T
p
r
o
tectio
n
is
m
u
ch
f
aster
,
o
p
er
ate
s
in
th
e
o
r
d
er
o
f
µsec,
a
n
d
allo
ws
o
n
ly
1
.
2
to
1
.
8
tim
es
o
f
r
ated
cu
r
r
e
n
t.
On
th
e
co
n
tr
ar
y
,
SC
R
s
witc
h
es
ar
e
m
u
c
h
s
lo
wer
th
a
n
I
GB
T
s
.
DE
SAT
(
d
e
-
s
atu
r
atio
n
)
p
r
o
tectio
n
f
o
r
id
en
tify
in
g
a
f
a
u
lt
co
n
d
itio
n
an
d
a
s
h
o
r
t
cir
cu
it
in
an
I
GB
T
is
u
s
e
d
in
th
e
p
r
o
tectio
n
o
f
in
v
er
ter
s
.
I
GB
T
will
b
e
at
d
e
-
s
atu
r
atio
n
co
n
d
itio
n
if
c
o
llecto
r
to
em
itter
v
o
ltag
e
ex
ce
e
d
s
ab
o
v
e
5
to
8
v
o
lts
an
d
th
e
g
ate
to
em
itter
v
o
ltag
e
is
h
ig
h
.
I
t
h
as
b
ee
n
p
o
in
ted
o
u
t
th
at
d
am
ag
e
t
o
th
e
s
em
ico
n
d
u
cto
r
d
ev
ices
o
f
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
2
5
2
-
8
8
1
4
I
n
t J Ad
v
Ap
p
l Sci
,
Vo
l.
10
,
No
.
3
,
Sep
tem
b
er
2
0
2
1
:
21
2
–
22
6
216
th
e
co
n
v
er
ter
is
ar
is
in
g
d
u
e
t
o
h
ea
v
y
d
is
ch
ar
g
e
o
f
d
c
s
id
e
f
ilter
ca
p
ac
ito
r
d
u
r
in
g
s
h
o
r
t
cir
cu
it
f
au
lts
.
I
t
is
s
u
g
g
ested
a
m
o
d
u
lated
lo
w
f
a
u
lt e
n
er
g
y
(
ML
E
)
p
r
o
tectio
n
s
ch
em
e
f
o
r
DC
d
is
tr
ib
u
tio
n
s
y
s
tem
[
4
5
]
As
an
ex
ce
p
tio
n
,
if
th
e
in
v
er
t
er
s
h
av
e
n
o
ab
ilit
y
to
lim
it
th
e
f
au
lt
cu
r
r
en
ts
,
th
e
n
f
u
s
es
an
d
n
o
-
f
u
s
e
cir
cu
it
b
r
ea
k
er
s
m
u
s
t
h
av
e
th
e
ca
p
ab
ilit
y
to
p
r
o
tect
t
h
e
in
v
er
ter
s
ag
ain
s
t
lin
e
-
to
-
lin
e
an
d
th
r
ee
-
p
h
ase
f
au
lts
in
th
e
u
n
-
g
r
o
u
n
d
e
d
L
VAC
m
icr
o
g
r
id
.
Dif
f
er
en
t
o
p
e
r
atin
g
p
r
i
n
cip
les
o
f
t
h
e
p
r
o
tectiv
e
r
elay
s
,
n
o
t
b
ased
o
n
h
i
g
h
f
au
lt
cu
r
r
e
n
t,
ar
e
s
elec
ted
ag
a
in
s
t
d
if
f
er
en
t
f
au
lts
an
d
d
if
f
er
en
t
g
r
o
u
n
d
in
g
ty
p
es
o
f
m
icr
o
g
r
id
s
,
s
u
ch
as
u
n
-
g
r
o
u
n
d
ed
,
u
n
i
-
g
r
o
u
n
d
e
d
,
an
d
m
u
lti
-
g
r
o
u
n
d
e
d
.
Fau
lt
cu
r
r
en
t
s
av
ailab
le
ar
e
v
er
y
less
,
o
n
ly
2
–
3
tim
es
th
e
f
u
ll
lo
ad
cu
r
r
en
t
o
r
ev
en
less
d
ep
en
d
in
g
o
n
co
n
tr
o
l
m
eth
o
d
o
f
co
n
v
er
ter
[
1
9
]
,
[
45
]
,
[
4
6
]
.
T
h
er
e
is
a
p
r
o
p
o
s
al
to
ad
o
p
t
a
cu
r
r
en
t
-
lim
it
m
eth
o
d
o
f
co
n
v
er
ter
co
n
tr
o
l
b
y
r
ed
u
ci
n
g
th
e
v
o
lta
g
e
in
th
e
f
au
lty
p
h
ase(
s
)
b
u
t
to
k
ee
p
th
e
v
o
ltag
e
o
f
h
ea
lt
h
y
p
h
ases
u
n
alter
ed
.
I
t
is
r
ep
o
r
te
d
th
at
a
f
ly
wh
ee
l
s
y
s
tem
with
in
v
er
ter
-
in
ter
f
ac
ed
DG
is
s
u
ited
to
s
u
p
p
ly
a
s
ig
n
if
ican
t c
u
r
r
en
t
[
19
]
,
[
29
]
,
[
30]
.
2
.
2
.
P
o
int
o
f
co
mm
o
n c
o
up
lin
g
(
P
CC)
T
h
e
m
icr
o
g
r
i
d
ju
r
is
d
ictio
n
s
tar
ts
f
r
o
m
s
ep
ar
atio
n
s
witch
(
C
B
)
o
f
PC
C
to
d
o
wn
war
d
,
s
ee
Fig
u
r
e
1
.
T
h
e
PC
C
is
,
u
s
u
ally
,
lo
c
ated
at
th
e
p
r
im
ar
y
s
id
e
o
f
u
tili
ty
tr
an
s
f
o
r
m
er
an
d
is
th
e
p
o
in
t
o
f
in
ter
co
n
n
ec
tio
n
/s
ep
ar
atio
n
wi
th
m
ain
(
o
r
u
tili
ty
)
g
r
id
[
4
7
]
,
[
4
8
]
.
I
t
ac
c
o
m
m
o
d
ates
ce
n
tr
al
co
n
tr
o
ller
,
p
r
o
tectiv
e
r
elay
s
/s
en
s
in
g
u
n
its
,
s
y
n
ch
r
o
n
izin
g
u
n
it
a
n
d
s
e
p
ar
atio
n
s
witch
.
T
h
e
ce
n
tr
al
co
n
tr
o
ller
c
o
n
s
is
ts
,
m
ain
l
y
,
o
f
two
m
o
d
u
les
-
en
er
g
y
m
an
ag
em
e
n
t
m
o
d
u
le
(
E
M
M)
an
d
p
r
o
tectio
n
co
o
r
d
in
atio
n
m
o
d
u
le
(
PC
M)
,
also
,
ca
lled
it
as
ce
n
tr
al
p
r
o
tectio
n
u
n
it
(
C
PU)
[
4
9
]
.
T
h
e
ce
n
tr
al
co
n
tr
o
ller
p
r
o
d
u
ce
s
th
e
in
f
o
r
m
ativ
e
d
ata
s
et
co
n
tain
in
g
t
h
e
n
etwo
r
k
to
p
o
lo
g
y
as we
ll a
s
lo
ca
tio
n
s
an
d
id
e
n
tifie
r
s
o
f
p
r
o
tectiv
e
r
elay
s
[
3
0
]
,
[
3
9
]
.
T
h
e
DG
-
u
tili
ty
in
ter
c
o
n
n
ec
tio
n
f
u
n
ctio
n
s
o
f
PC
M
ar
e
t
h
r
ee
-
f
o
ld
s
:
i)
d
is
co
n
n
ec
tio
n
o
f
D
G
f
r
o
m
th
e
m
ain
g
r
i
d
,
if
r
eq
u
ir
ed
;
ii)
p
r
o
tectio
n
o
f
th
e
m
icr
o
g
r
id
d
u
e
to
f
au
lt
cu
r
r
en
t
s
u
p
p
lied
b
y
DGs
wh
en
t
h
e
f
a
u
lt
a
nd
tr
an
s
ien
t o
v
er
v
o
ltag
e
ar
is
en
at
th
e
m
ain
g
r
i
d
; a
n
d
iii)
p
r
o
tecti
o
n
o
f
DG
f
r
o
m
th
e
d
am
ag
e
,
ar
is
en
esp
ec
ially
d
u
e
to
au
to
m
atic
r
ec
lo
s
in
g
[
5
0
]
-
[
5
3
]
.
T
h
e
s
en
s
in
g
u
n
its
o
f
PC
M
ar
e
s
ev
er
al
lik
e
c
u
r
r
en
t
s
en
s
in
g
u
n
it
(
C
SU)
,
ze
r
o
cr
o
s
s
in
g
d
etec
tio
n
u
n
it
,
r
elay
s
ettin
g
s
u
p
d
ater
f
o
r
ad
a
p
tiv
e
p
r
o
tectio
n
s
y
s
tem
,
s
en
s
o
r
f
o
r
u
n
d
er
/
o
v
er
(
U/O)
v
o
ltag
e,
lo
s
s
o
f
g
r
id
(
L
OG
)
p
r
o
tectio
n
s
ch
em
es
[
5
4
]
,
[
5
5
]
.
T
h
e
C
SU
m
ea
s
u
r
es
th
e
n
etwo
r
k
cu
r
r
en
ts
with
th
e
p
u
r
p
o
s
e
o
f
d
etec
tin
g
ac
tu
al
f
au
lts
an
d
tak
es
m
o
r
e
th
an
s
ev
en
cy
cles
to
a
v
o
id
tr
a
n
s
ien
t
s
itu
atio
n
o
f
DG
r
ec
o
n
n
ec
tio
n
[
4
]
,
[
5
6
]
.
T
h
e
u
n
d
er
/o
v
er
f
r
eq
u
e
n
cy
o
f
th
e
PC
C
cu
r
r
en
t
wav
ef
o
r
m
is
d
eter
m
in
ed
b
y
ze
r
o
cr
o
s
s
in
g
d
etec
tio
n
u
n
it.
R
ate
o
f
ch
an
g
e
o
f
f
r
eq
u
e
n
cy
(
R
OC
O
F)
r
elay
,
with
a
1
.
0
Hz/sec
th
r
esh
o
ld
,
s
en
d
s
a
tr
ip
s
ig
n
al
to
th
e
PC
C
cir
cu
it b
r
ea
k
er
(
C
B
)
[
4
]
,
[
8]
.
Af
ter
th
e
f
au
lt
clea
r
an
ce
,
au
to
m
atic
s
y
n
ch
r
o
n
izatio
n
u
n
it
b
e
co
m
es
ac
tiv
e
f
o
r
r
esto
r
atio
n
o
f
th
e
m
ain
g
r
id
r
ec
o
n
n
ec
tio
n
-
v
o
ltag
e,
f
r
eq
u
en
cy
an
d
p
h
ase
an
g
le
o
f
b
o
th
g
r
id
s
m
u
s
t
b
e
m
atch
ed
with
in
ac
ce
p
tab
le
lim
its
.
Pre
f
er
ab
ly
,
au
to
m
atic
r
e
-
s
y
n
ch
r
o
n
izatio
n
s
ch
em
e
wo
r
k
s
with
co
m
m
u
n
icatio
n
n
etw
o
r
k
[
7
]
,
[
19
]
,
[
57
]
,
[
5
8
]
.
PC
C
s
ep
ar
atio
n
s
witch
is
a
h
ig
h
-
s
p
ee
d
b
r
ea
k
er
.
Hi
g
h
s
p
ee
d
is
r
eq
u
ir
e
d
to
m
ai
n
tain
th
e
m
ic
r
o
g
r
id
s
tab
ilit
y
ag
ain
s
t
f
au
lts
o
n
th
e
m
ain
g
r
id
o
r
with
in
Mic
r
o
g
r
id
.
E
s
p
ec
ially
,
v
o
ltag
e
s
en
s
itiv
e
D
-
DGs
m
ay
en
d
an
g
e
r
th
e
Mic
r
o
g
r
id
s
tab
ilit
y
.
“T
r
an
s
f
er
tr
ip
”
s
ch
em
e
is
in
co
r
p
o
r
ate
d
in
th
is
b
r
ea
k
er
to
av
o
id
n
u
is
an
ce
s
ep
ar
atio
n
an
d
p
r
o
v
id
in
g
f
ast
tr
ip
p
in
g
.
Fo
r
h
ig
h
s
p
ee
d
o
p
er
at
io
n
,
a
s
tatic
s
wi
tch
-
eith
er
SC
R
b
as
ed
o
r
I
GB
T
-
b
ased
is
u
s
ed
[
1
9
]
,
[
45
]
,
[
57
]
-
[
63]
.
2
.
3
.
T
ra
ns
f
o
rm
er
s
A
m
icr
o
g
r
id
h
as
a
n
u
m
b
e
r
o
f
tr
a
n
s
f
o
r
m
er
s
f
o
r
d
if
f
er
e
n
t
u
s
ag
e
–
u
tili
ty
tr
a
n
s
f
o
r
m
e
r
,
is
o
latio
n
tr
an
s
f
o
r
m
er
,
an
d
s
m
ar
t
tr
an
s
f
o
r
m
er
.
T
h
ese
tr
an
s
f
o
r
m
er
s
ar
e
th
r
ee
p
h
ase
o
r
s
in
g
le
-
p
h
ase
ty
p
es.
T
h
e
t
y
p
e
s
o
f
win
d
in
g
c
o
n
n
ec
tio
n
s
o
f
t
h
e
t
h
r
ee
p
h
ase
tr
an
s
f
o
r
m
er
s
h
av
e
im
p
o
r
tan
t
ef
f
ec
t
o
n
th
e
p
r
o
t
ec
tio
n
ty
p
e.
T
h
ese
tr
an
s
f
o
r
m
er
s
ar
e
r
ev
iewe
d
in
th
e
f
o
llo
win
g
s
ec
tio
n
s
.
2
.
3
.
1
.
Ut
ility
(
m
a
in)
t
ra
ns
f
o
rm
er
/d
is
t
ributio
n t
ra
ns
f
o
rm
er
I
t
is
,
u
s
u
ally
,
lo
ca
ted
n
ex
t
to
P
C
C
at
th
e
m
icr
o
g
r
id
s
id
e,
s
ee
Fig
u
r
e
1
.
I
t
is
a
MV
/LV
tr
an
s
f
o
r
m
er
f
o
r
L
V
m
icr
o
g
r
id
.
R
eg
a
r
d
in
g
tr
a
n
s
f
o
r
m
er
c
o
n
n
ec
tio
n
,
th
e
r
ese
ar
ch
er
s
h
av
e
r
e
p
o
r
te
d
m
an
y
p
o
in
ts
.
Fo
r
Y
-
g
/Y
-
g
tr
an
s
f
o
r
m
er
co
n
n
ec
tio
n
,
th
er
e
is
a
f
lo
w
o
f
ze
r
o
s
eq
u
en
ce
cu
r
r
en
t
in
th
e
lin
e.
I
f
∆/Y
-
g
c
o
n
n
ec
tio
n
,
with
d
elta
o
n
th
e
DG
-
s
id
e,
is
u
s
ed
th
en
f
lo
w
o
f
ze
r
o
s
eq
u
e
n
ce
cu
r
r
e
n
t
in
th
e
lin
e
will
b
e
s
to
p
p
ed
an
d
SEM
I
F4
7
v
o
ltag
e
s
tan
d
ar
d
will
b
e
m
ain
tain
ed
.
T
h
e
latter
co
n
n
ec
tio
n
ac
ts
as
a
s
elf
-
g
r
o
u
n
d
s
o
u
r
ce
,
b
u
t
n
o
t
th
e
f
o
r
m
er
.
∆/Y
-
g
co
n
n
ec
tio
n
is
claim
ed
m
o
s
t
e
f
f
ec
tiv
e
f
o
r
s
in
g
le
-
lin
e
-
to
-
g
r
o
u
n
d
f
a
u
lts
o
n
th
e
d
elta
s
id
e
a
n
d
lo
ad
s
co
n
n
ec
ted
lin
e
-
to
-
n
eu
tr
al
o
n
th
e
wy
e
s
id
e
[
7
]
,
[
30
]
,
[
53
]
,
[
60
]
,
[
6
4
]
.
R
esear
ch
er
s
,
also
,
r
ep
o
r
ted
w
h
en
f
au
lt
o
cc
u
r
s
o
n
th
e
MV
s
id
e
o
f
th
e
tr
an
s
f
o
r
m
er
,
t
h
e
m
icr
o
g
r
id
is
is
lan
d
ed
f
r
o
m
th
e
PC
C
,
an
d
s
till
f
au
lt
cu
r
r
en
t
is
f
ed
b
y
th
e
DGs.
I
t
is
s
u
g
g
ested
th
at
r
elay
s
at
t
h
e
L
V
s
id
e
s
h
o
u
ld
is
o
late
DGs
f
r
o
m
th
e
MV
s
y
s
tem
,
b
u
t
co
n
tin
u
e
to
s
u
p
p
l
y
th
e
lo
ca
l lo
ad
s
[
7
]
,
[
6
5
]
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t J Ad
v
Ap
p
l Sci
I
SS
N:
2
2
5
2
-
8
8
1
4
R
ev
iew
o
f p
r
o
tectio
n
a
s
p
ec
ts
o
f m
icro
g
r
id
d
ev
ices
(
A
s
h
o
ke
K
u
ma
r
B
a
s
u
)
217
2
.
3
.
2
.
I
s
o
la
t
io
n t
ra
ns
f
o
rm
er
s
An
I
s
o
latio
n
t
r
an
s
f
o
r
m
e
r
is
in
te
r
p
o
s
ed
b
etwe
en
DG
-
s
o
u
r
ce
b
r
an
ch
es
a
n
d
c
o
m
m
o
n
AC
b
u
s
es
in
th
e
AC
m
icr
o
g
r
id
(
“I
s
o
-
T
r
”
in
Fig
u
r
e
1
)
.
I
t
elim
in
ates
d
c
-
cu
r
r
e
n
t
co
m
p
o
n
en
ts
g
en
er
ated
b
y
in
v
er
ter
.
I
t
is
,
m
ain
ly
,
a
s
tep
-
u
p
tr
an
s
f
o
r
m
er
with
DE
R
s
id
e
at
lo
wer
v
o
ltag
e
[
1
2
]
,
[
3
6
]
.
B
ac
k
-
f
e
ed
o
f
o
v
er
v
o
ltag
e,
r
ela
y
co
o
r
d
in
atio
n
,
u
n
b
alan
ce
d
f
ee
d
er
lo
ad
s
,
g
r
o
u
n
d
in
g
r
elay
in
g
f
o
r
f
ee
d
er
s
,
to
n
a
m
e
a
f
ew,
ar
e
th
e
d
ec
id
in
g
f
ac
t
o
r
s
f
o
r
th
is
tr
an
s
f
o
r
m
er
c
o
n
n
ec
tio
n
.
L
ik
e
u
tili
ty
tr
an
s
f
o
r
m
e
r
if
t
h
is
tr
an
s
f
o
r
m
er
is
co
n
n
ec
ted
i
n
∆/∆
o
r
∆/Y
-
g
with
DE
R
s
id
e
d
elta,
th
en
tr
an
s
f
o
r
m
er
ac
ts
as
a
g
r
o
u
n
d
s
o
u
r
ce
an
d
n
o
ze
r
o
s
eq
u
en
ce
cu
r
r
en
t
f
lo
ws
th
r
o
u
g
h
t
h
e
f
ee
d
er
.
T
h
is
tr
an
s
f
o
r
m
er
is
,
a
ls
o
,
u
s
ed
to
m
ak
e
d
if
f
er
e
n
t
c
o
n
f
ig
u
r
atio
n
o
f
AC
m
icr
o
g
r
id
s
,
lik
e
3
-
p
h
ase
an
d
4
-
wir
e,
3
-
p
h
ase
an
d
3
-
wir
e,
1
-
p
h
ase
an
d
2
-
wir
e,
o
r
1
-
p
h
ase
a
n
d
3
-
wir
e
[7
]
,
[
6
0
]
.
2
.
3
.
3
.
Sm
a
rt
o
r
s
o
lid
-
s
t
a
t
e
t
ra
ns
f
o
r
m
er
s
(
SS
T
)
SS
T
s
ar
e
th
r
ee
-
p
o
r
t
p
o
wer
ele
ctr
o
n
ic
ex
ch
a
n
g
er
h
a
v
in
g
th
r
e
e
-
lay
er
co
n
v
er
s
io
n
s
:
HV
DC
li
n
k
,
L
VDC
lin
k
an
d
AC
lin
k
,
s
ee
Fig
u
r
e
2
.
I
t
ac
ts
a
s
a
s
o
lid
-
s
tate
p
lu
g
-
an
d
-
p
lay
in
ter
f
ac
e.
T
h
e
Ma
s
s
ac
h
u
s
etts
I
n
s
titu
te
o
f
T
ec
h
n
o
lo
g
y
(
MI
T
)
h
as
s
elec
ted
it
as
o
n
e
o
f
th
e
b
est
tech
n
o
lo
g
ies
o
f
2
0
1
0
[
6
4
]
.
FR
E
E
DM
m
icr
o
g
r
id
is
a
lo
o
p
ed
o
n
e
,
h
av
in
g
r
e
n
ewa
b
le
DGs,
E
Ses
,
p
o
wer
elec
tr
o
n
ic
d
e
v
ices,
an
d
l
o
ad
s
o
f
b
o
th
i
n
d
u
s
tr
ial
a
n
d
r
esid
en
tial
ty
p
es.
I
n
FR
E
E
DM
n
etwo
r
k
,
th
er
e
is
a
p
r
o
b
lem
s
o
f
b
i
-
d
ir
ec
tio
n
al
p
o
wer
f
lo
w,
u
n
b
alan
cin
g
d
u
e
to
s
in
g
le
p
h
ase
DGs
as
well
as
l
o
ad
s
,
an
d
r
en
ewa
b
le
DGs
with
DC
o
u
tp
u
t.
Du
e
t
o
th
ese
p
r
o
b
lem
s
,
th
er
e
ar
is
es
h
ar
m
o
n
ics,
s
atu
r
atio
n
o
f
tr
a
n
s
f
o
r
m
er
,
p
o
o
r
p
o
wer
f
ac
to
r
,
to
n
am
e
a
f
ew.
SS
T
s
tak
e
ca
r
e
o
f
th
ese
p
r
o
b
le
m
s
,
r
ep
lacin
g
tr
a
d
itio
n
al
tr
an
s
f
o
r
m
er
s
.
SS
T
s
ca
n
p
lay
a
cr
u
cial
r
o
le
in
m
icr
o
g
r
id
p
r
o
tectio
n
d
u
r
in
g
o
v
e
r
lo
ad
s
an
d
d
is
to
r
tio
n
s
.
I
ts
ca
p
ab
ilit
y
an
d
d
esig
n
h
elp
m
in
im
izin
g
cir
c
u
it
an
d
co
m
m
u
n
icatio
n
f
o
r
s
u
cc
ess
f
u
l
p
r
o
tectio
n
s
tr
ateg
y
[
4
]
,
[
66
]
,
[
67]
.
Fig
u
r
e
2
.
R
ep
r
esen
tatio
n
o
f
s
o
lid
-
s
tate
tr
an
s
f
o
r
m
er
s
(
SS
T
)
2
.
4
.
F
ee
ders/
bra
nc
hes
a
nd
t
o
po
lo
g
y
A
m
icr
o
g
r
id
h
as
a
n
u
m
b
e
r
o
f
f
ee
d
er
s
a
n
d
th
ese
f
ee
d
er
s
ar
e
d
iv
id
e
d
in
to
v
a
r
io
u
s
zo
n
es
to
f
ac
ilit
ate
p
r
o
tectio
n
o
f
th
e
m
icr
o
g
r
id
f
o
r
b
o
th
g
r
i
d
-
co
n
n
ec
ted
a
n
d
au
to
n
o
m
o
u
s
m
o
d
es
[
1
9
]
.
Fo
r
z
o
n
i
n
g
o
f
th
ese
f
ee
d
er
s
,
it
is
k
ep
t
in
m
in
d
th
at
th
er
e
is
an
ap
p
r
o
p
r
iate
b
alan
ce
b
etwe
en
DGs
an
d
lo
ad
s
in
ea
ch
z
o
n
e.
On
au
to
n
o
m
o
u
s
m
o
d
e,
to
tal
DG
ca
p
ac
ity
o
f
an
y
zo
n
e
is
to
b
e
k
ep
t
s
li
g
h
tly
h
ig
h
er
th
an
lo
ad
-
r
ea
s
o
n
is
to
m
ee
t
m
ax
im
u
m
lo
ad
o
f
th
e
zo
n
e
an
d
to
is
o
late
th
e
m
in
im
u
m
s
ec
tio
n
o
f
th
e
r
a
d
ial
f
ee
d
er
to
elim
in
ate
th
e
f
au
lt.
I
n
ea
ch
zo
n
e
,
th
er
e
m
u
s
t
b
e
at
least
o
n
e
lar
g
est
D
G
ca
p
ac
ity
to
ad
ju
s
t
l
o
ad
f
r
eq
u
en
cy
.
E
ac
h
zo
n
e
n
ee
d
s
f
ast
o
p
er
atin
g
s
witch
es,
s
u
b
-
s
tatio
n
b
r
ea
k
er
,
s
y
n
c
h
r
o
n
izatio
n
-
ch
ec
k
r
elay
s
,
an
d
co
m
m
u
n
icatio
n
f
ac
ilit
y
[
1
9
]
,
[
4
8
]
.
T
h
e
r
esear
ch
er
s
r
ep
o
r
ted
th
at
im
p
e
d
an
ce
o
f
a
f
ee
d
er
,
as
m
ea
s
u
r
ed
,
v
ar
ies
s
ig
n
if
ican
tly
u
n
d
er
d
if
f
er
e
n
t
co
n
d
itio
n
s
,
s
u
c
h
as
n
o
r
m
al
o
p
er
atio
n
an
d
f
au
l
ty
co
n
d
itio
n
s
.
T
h
is
m
ea
s
u
r
ed
v
a
lu
e
is
,
also
,
d
if
f
er
en
t
u
n
d
e
r
in
ter
n
al
f
au
lts
,
an
d
ex
ter
n
al
f
au
lts
.
I
n
th
e
r
esear
ch
wo
r
k
s
,
two
ty
p
es
o
f
f
ee
d
er
h
av
e
b
ee
n
a
d
d
r
ess
ed
-
s
in
g
l
e
-
en
d
f
ee
d
i
n
g
an
d
d
o
u
b
le
-
e
n
d
.
I
t
is
r
ep
o
r
te
d
th
at
m
ea
s
u
r
em
en
t
o
f
im
p
e
d
an
ce
f
o
r
a
s
in
g
le
-
e
n
d
f
ee
d
er
is
r
ath
er
s
im
p
le
co
m
p
ar
ed
to
d
o
u
b
le
-
en
d
f
ee
d
er
s
.
I
n
th
e
f
o
r
m
er
(
s
in
g
le
-
en
d
)
f
ee
d
er
,
th
e
f
au
lt
r
esis
tan
ce
ad
d
ed
with
th
e
r
ea
l
p
ar
t
o
f
th
e
im
p
ed
an
ce
,
b
u
t
f
o
r
a
later
(
i.e
.
,
d
o
u
b
le
-
e
n
d
f
ee
d
er
)
th
e
co
m
p
licac
y
in
t
h
e
m
ea
s
u
r
e
m
en
t
o
f
im
p
ed
a
n
ce
ar
is
es
du
e
to
ty
p
e
o
f
in
ter
n
al
f
a
u
lts
an
d
its
r
elatio
n
s
h
ip
with
f
au
lt
ty
p
e,
f
au
lt
cu
r
r
en
t,
an
d
f
au
lt
r
esis
tan
ce
.
W
h
er
ea
s
f
o
r
a
s
o
lid
f
au
lt,
th
e
m
ea
s
u
r
ed
im
p
ed
an
ce
co
n
tain
s
o
n
l
y
lin
e
r
esis
tan
ce
an
d
r
ea
ctan
ce
.
I
t
is
,
al
s
o
,
r
ep
o
r
ted
if
th
e
f
au
lt
r
esis
tan
ce
in
cr
ea
s
es,
th
en
th
e
m
ea
s
u
r
ed
im
p
ed
a
n
ce
o
f
th
e
f
ee
d
er
will
r
is
e
u
p
to
a
cr
itical
p
o
in
t
an
d
th
er
ea
f
ter
d
ec
ay
[
6
8
]
.
As
th
e
im
p
ed
an
ce
o
f
th
e
f
ee
d
er
s
is
lo
w
o
n
ac
tiv
e
d
is
tr
ib
u
ted
n
etwo
r
k
s
(
ADNs)
,
it
i
s
n
o
t
ea
s
y
to
esti
m
ate
th
e
f
au
lt
d
ir
ec
tio
n
u
n
d
e
r
th
r
ee
-
p
h
ase
f
au
lts
.
Als
o
,
f
o
r
u
n
-
g
r
o
u
n
d
m
icr
o
g
r
i
d
,
th
er
e
is
a
s
h
if
t
o
f
n
eu
tr
al
p
o
i
n
t a
s
th
e
f
au
lt c
u
r
r
e
n
t in
th
e
f
ee
d
er
co
n
tain
s
DC
o
f
f
s
et
[
6
8
]
,
[
6
9
]
.
2
.
4
.
1
.
DG
-
s
o
urce
bra
nches
T
h
e
ca
b
le
h
as
g
r
ea
ter
im
p
ed
a
n
ce
th
a
n
th
e
o
v
er
h
ea
d
lin
e.
W
h
en
DG
is
co
n
n
ec
ted
with
o
v
er
h
ea
d
lin
e
f
ee
d
er
,
i
t
af
f
ec
ts
m
o
s
t
th
e
g
r
id
co
n
tr
ib
u
tio
n
to
th
e
f
au
lt
cu
r
r
e
n
t
[
7
0
]
.
DGs
ar
e
o
f
v
a
r
io
u
s
ty
p
es
s
u
ch
as
C
-
DG
an
d
D
-
DG.
Fau
lts
in
th
e
m
icr
o
g
r
id
f
ee
d
e
r
ar
e
o
f
d
if
f
er
e
n
t ty
p
es
-
SLG
(
s
in
g
le
lin
e
to
g
r
o
u
n
d
)
,
lin
e
-
to
-
lin
e
(
L
L
)
.
Fau
lt
cu
r
r
en
t
in
v
ar
io
u
s
s
ec
tio
n
s
o
f
th
e
f
ee
d
er
s
d
ep
en
d
s
o
n
b
o
th
DG
an
d
f
au
lt
ty
p
es.
As
p
er
th
e
r
esear
ch
er
s
,
f
ee
d
er
p
r
o
tectio
n
s
u
tili
ze
s
eq
u
en
ce
c
u
r
r
en
t
an
d
v
o
ltag
e
c
o
m
p
o
n
e
n
ts
(
i.e
.
p
o
s
itiv
e,
n
eg
at
iv
e
an
d
ze
r
o
)
,
to
tal
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
2
5
2
-
8
8
1
4
I
n
t J Ad
v
Ap
p
l Sci
,
Vo
l.
10
,
No
.
3
,
Sep
tem
b
er
2
0
2
1
:
21
2
–
22
6
218
h
ar
m
o
n
ic
d
is
to
r
tio
n
lev
els o
f
p
h
ase
cu
r
r
en
ts
an
d
v
o
ltag
es.
N
eg
ativ
e
s
eq
u
en
ce
cu
r
r
e
n
t a
n
d
v
o
ltag
e
co
m
p
o
n
en
ts
an
d
T
HD
lev
els
o
f
cu
r
r
en
t
an
d
v
o
ltag
e
o
f
f
a
u
lted
p
h
ase
ar
e
r
ep
o
r
ted
a
s
ig
n
if
ican
t
in
cr
ea
s
e
af
ter
th
e
f
au
lt
in
ce
p
tio
n
tim
e
o
f
5
0
th
s
ec
o
n
d
.
I
f
s
h
o
r
t
-
cir
c
u
it
cu
r
r
en
ts
is
co
n
s
id
er
ed
f
o
r
f
ee
d
er
p
r
o
tectio
n
s
,
th
er
e
ar
is
e
s
er
io
u
s
p
r
o
b
le
m
s
lik
e
r
is
in
g
o
f
u
n
d
etec
ted
f
au
lts
,
n
o
n
-
c
o
o
r
d
in
ated
tr
ip
p
in
g
,
r
ed
u
ctio
n
o
f
r
ea
ch
o
f
r
elay
,
f
ailu
r
e
o
f
f
u
s
e
s
av
in
g
.
C
-
DG
s
o
u
r
ce
b
r
a
n
ch
e
s
(
e.
g
.
,
th
e
b
atter
y
-
e
n
er
g
y
s
to
r
ag
e
an
d
m
ic
r
o
-
tu
r
b
in
e
s
o
u
r
c
e
b
r
an
c
h
es)
in
th
e
m
icr
o
g
r
id
co
n
tain
s
p
o
wer
in
v
er
ter
s
.
T
h
ese
p
o
wer
in
v
e
r
ter
s
lim
it
th
e
f
a
u
lt
cu
r
r
en
ts
in
t
o
th
e
f
au
lted
PV
-
s
o
u
r
ce
lo
ca
ted
at
th
e
o
th
e
r
b
r
a
n
ch
[
8
]
,
[
12
]
,
[
3
6
]
.
2
.
4
.
2
.
L
o
a
d bra
nches
Mic
r
o
g
r
id
l
o
ad
s
ar
e
o
f
d
if
f
e
r
e
n
t
ty
p
es,
s
u
ch
as
s
tatic
an
d
d
y
n
am
ic
lo
a
d
s
.
L
o
a
d
s
ac
t
u
n
d
e
r
d
if
f
e
r
en
t
co
n
d
itio
n
s
o
f
s
tar
tin
g
,
a
n
d
h
av
e
d
if
f
e
r
en
t
ca
p
ac
ities
,
an
d
p
o
wer
f
ac
to
r
s
.
T
o
tack
le
al
l
th
ese
s
itu
atio
n
s
,
d
if
f
er
en
t
r
ela
y
ch
ar
ac
ter
is
tics
,
s
u
ch
as
o
v
er
cu
r
r
en
t
r
elay
,
u
n
d
er
-
v
o
lta
g
e
r
elay
,
n
eg
ativ
e
s
e
q
u
en
ce
-
b
ased
r
elay
,
an
d
T
HD
b
ased
r
elay
ar
e
s
el
ec
ted
.
T
h
ese
r
elay
ch
ar
ac
ter
is
tics
ar
e
ch
o
s
en
to
o
b
tain
th
e
h
ig
h
co
-
o
r
d
in
atio
n
,
d
is
cr
im
in
atio
n
,
r
eliab
ilit
y
an
d
f
ast
o
p
er
atio
n
o
f
th
e
p
r
o
tectio
n
s
y
s
tem
.
Fo
r
lo
ad
b
r
an
ch
es
h
ig
h
-
s
p
ee
d
f
u
s
es
ar
e
ef
f
ec
tiv
ely
u
s
ed
in
co
-
o
r
d
in
atio
n
with
o
v
er
-
c
u
r
r
en
t
r
elay
.
Fe
ed
er
,
wh
er
e
f
r
o
m
lo
ad
b
r
a
n
ch
is
b
r
o
u
g
h
t
o
u
t
,
s
ee
Fig
u
r
e.
3
,
h
as
lim
ited
c
u
r
r
e
n
t
ca
r
r
y
in
g
ca
p
ac
ity
.
L
o
ad
s
witch
es
ar
e
u
s
ed
an
d
h
av
e
lim
ited
ca
r
r
y
in
g
ca
p
a
city
,
co
m
p
ar
ed
to
b
r
ea
k
er
a
n
d
r
ec
l
o
s
er
[
1
2
]
,
[
3
6
]
.
2
.
4
.
3
.
T
runk
f
ee
ders
T
r
u
n
k
f
ee
d
er
is
th
e
m
ain
lin
e
(
Fig
u
r
e
3
)
.
L
o
ad
b
r
an
c
h
is
n
o
t
allo
wed
to
co
n
n
ec
t
all
t
h
r
o
u
g
h
th
e
len
g
th
o
f
AC
tr
u
n
k
lin
e.
T
h
er
e
ar
e
v
ar
io
u
s
ty
p
es
o
f
f
au
lts
o
cc
u
r
r
ed
in
th
e
AC
tr
u
n
k
lin
e,
w
h
ich
ar
e
s
in
g
le
-
lin
e
to
g
r
o
u
n
d
(
SLG)
f
au
lts
,
d
o
u
b
le
-
lin
e
to
g
r
o
u
n
d
(
L
L
G)
f
au
lt
s
,
an
d
lin
e
-
to
-
lin
e
(
L
L
)
.
Fo
r
th
e
f
ir
s
t
two
g
r
o
u
n
d
f
au
lts
at
th
e
g
r
id
-
co
n
n
ec
ted
m
o
d
e
o
f
a
u
n
i
-
g
r
o
u
n
d
ed
m
icr
o
g
r
id
,
f
au
lt
cu
r
r
e
n
t
f
lo
ws
f
r
o
m
f
au
lted
lo
ca
tio
n
b
ac
k
to
th
e
g
r
o
u
n
d
ed
n
eu
tr
al
o
f
th
e
d
is
tr
ib
u
tio
n
tr
an
s
f
o
r
m
er
.
T
h
is
f
au
lt
cu
r
r
en
t
m
a
g
n
itu
d
e
v
a
r
ie
s
with
th
e
ty
p
e
o
f
DGs
–
m
o
r
e
f
o
r
th
e
D
-
DGs
th
an
C
-
DGs.
Ag
ain
,
f
o
r
lo
w
im
p
ed
an
ce
L
L
f
a
u
lts
,
f
au
lt
cu
r
r
e
n
t
is
h
ig
h
en
o
u
g
h
t
o
o
p
er
ate
o
v
er
-
c
u
r
r
en
t
r
elay
.
T
h
e
r
esear
ch
er
s
r
e
p
o
r
ted
th
at
th
e
r
e
ar
e
s
ig
n
if
ica
n
t
n
eg
ativ
e
s
eq
u
en
ce
cu
r
r
en
t
a
n
d
v
o
ltag
e
c
o
m
p
o
n
en
ts
an
d
T
HD
o
f
p
h
ase
v
o
ltag
e
a
n
d
cu
r
r
e
n
t h
elp
in
g
p
r
o
tectio
n
s
o
lu
tio
n
s
f
o
r
b
o
t
h
u
n
-
g
r
o
u
n
d
ed
an
d
u
n
i
-
g
r
o
u
n
d
e
d
m
icr
o
g
r
id
s
.
T
h
e
T
HD
v
alu
e
at
th
e
f
au
lted
p
h
ase
is
co
m
p
ar
ativ
ely
m
o
r
e
th
an
th
e
h
ea
lth
y
p
h
ases
an
d
h
elp
s
d
etec
t
th
e
f
a
u
lts
.
Fo
r
n
eg
ativ
e
s
eq
u
e
n
ce
p
r
o
tectio
n
,
ca
r
ef
u
l
ev
alu
atio
n
o
f
its
th
r
esh
o
ld
v
alu
e
is
im
p
o
r
tan
t to
av
o
id
m
a
l
-
o
p
er
atio
n
u
n
d
er
u
n
b
alan
ce
d
lo
ad
c
o
n
d
itio
n
s
[
1
2
]
,
[
3
6
]
.
2
.
4
.
4
.
T
o
po
lo
g
y
T
o
p
o
lo
g
y
is
o
n
e
o
f
t
h
e
m
o
s
t
im
p
o
r
tan
t
f
ac
to
r
s
o
n
wh
ich
p
r
o
tectio
n
s
tr
ateg
ies
in
m
icr
o
g
r
i
d
d
ep
en
d
s
.
I
t
af
f
ec
ts
b
o
th
t
h
e
f
au
lt
c
u
r
r
e
n
t
d
ir
ec
tio
n
a
n
d
m
a
g
n
itu
d
e
.
T
h
e
s
tr
u
ctu
r
e
o
f
a
m
icr
o
g
r
i
d
is
o
f
d
if
f
er
en
t
t
y
p
es
-
r
ad
ial,
lo
o
p
ed
,
m
esh
ed
o
r
m
ix
ed
.
T
h
e
s
tr
u
ctu
r
e
is
also
an
im
p
o
r
tan
t p
ar
t o
f
to
p
o
lo
g
y
.
Fau
lt
cu
r
r
e
n
t
at
d
if
f
er
en
t
to
p
o
lo
g
ies
v
a
r
ies
an
d
s
am
e
t
o
p
o
lo
g
y
,
s
ay
l
o
o
p
s
tr
u
ct
u
r
e,
h
as
d
if
f
er
en
t
c
u
r
r
e
n
t
in
d
i
f
f
e
r
en
t
p
ath
s
an
d
th
e
p
r
o
tectiv
e
d
e
v
ice
s
o
n
th
o
s
e
p
ath
s
s
en
s
e
d
if
f
er
en
t
cu
r
r
en
ts
[
4
]
,
[
7
1
]
.
T
h
er
e
ar
e
s
ev
er
al
r
ea
s
o
n
s
f
o
r
ch
a
n
g
e
o
f
m
icr
o
g
r
id
to
p
o
lo
g
y
d
u
e
to
v
a
r
io
u
s
co
n
tr
o
l
ac
tio
n
s
,
n
am
ely
,
s
h
ed
d
in
g
o
f
lo
ad
s
d
u
r
in
g
p
ea
k
-
h
o
u
r
s
o
r
ad
d
itio
n
o
f
DG
f
o
r
en
e
r
g
y
ex
p
o
r
t
to
u
tili
ty
f
o
r
o
p
tim
u
m
an
d
ec
o
n
o
m
i
ca
l
o
p
er
atio
n
o
f
Mic
r
o
g
r
id
[
1
9
]
.
T
h
e
m
o
s
t
cr
u
cial
ch
allen
g
e
in
m
icr
o
g
r
i
d
p
r
o
tec
tio
n
is
th
e
u
n
ce
r
tain
ty
in
m
icr
o
g
r
id
to
p
o
lo
g
y
[
4
]
.
Mo
s
t
p
r
esen
ted
m
eth
o
d
s
ca
n
n
o
t
co
v
er
all
o
p
e
r
atio
n
al
to
p
o
l
o
g
ies
o
f
m
icr
o
g
r
id
.
T
h
er
e
is
a
co
n
ce
p
t
o
f
m
u
lti
-
m
ic
r
o
g
r
i
d
s
wh
ich
c
o
n
s
is
ts
o
f
a
n
u
m
b
er
o
f
DGs
an
d
L
V
m
icr
o
g
r
id
s
th
at
ar
e
co
n
n
ec
ted
t
o
th
e
MV
d
is
tr
ib
u
tio
n
s
u
p
p
ly
.
B
o
th
r
ad
ial
an
d
lo
o
p
ed
m
icr
o
g
r
id
s
m
u
s
t
h
av
e
t
h
e
ca
p
ab
ilit
y
o
f
p
r
o
tectio
n
ag
ain
s
t
d
i
f
f
er
en
t
ty
p
es
o
f
f
au
lts
in
ad
d
itio
n
to
s
in
g
le
-
p
h
ase
tr
ip
p
in
g
.
DC
m
icr
o
g
r
id
is
co
m
p
r
is
ed
o
f
DC
lo
ad
s
,
e
n
er
g
y
s
to
r
ag
e
elem
en
ts
,
an
d
DG
h
av
in
g
DC
o
u
tp
u
t
v
o
ltag
e
[
4
]
.
Prim
ar
y
p
r
o
tectio
n
s
ch
em
es
o
f
r
ad
ial
L
V
DC
m
icr
o
g
r
id
en
co
m
p
ass
co
n
v
er
ter
,
b
atter
y
,
an
d
f
ee
d
er
ag
ain
s
t p
o
le
-
to
-
p
o
le
an
d
p
o
le
-
to
-
g
r
o
u
n
d
f
au
lts
[
2
]
,
[
7
2
]
.
2
.
5
.
Switc
hes
-
circ
u
it
b
re
a
k
er
s
,
re
clo
s
er
s
,
s
ec
t
io
na
lis
er
s
a
n
d
f
u
s
es
Switch
es,
wh
ich
ar
e
co
m
m
er
cially
av
ailab
le
f
o
r
p
r
o
tectio
n
o
f
b
o
th
DC
an
d
AC
m
icr
o
g
r
id
s
,
ar
e,
m
ain
ly
,
m
o
ld
ed
-
ca
s
e
cir
c
u
it
b
r
ea
k
er
s
(
MCC
B
)
,
lo
w
-
v
o
lta
g
e
C
B
s
,
an
d
is
o
lated
-
ca
s
e
C
B
s
[
2
]
,
[
4
]
,
[
7
3
]
.
Gen
er
ally
,
AC
b
r
ea
k
er
s
ar
e
m
u
ch
ch
ea
p
e
r
th
an
d
c
b
r
ea
k
e
r
s
.
AC
b
r
ea
k
er
s
d
ep
en
d
o
n
th
e
n
atu
r
al
ze
r
o
o
f
AC
cu
r
r
en
t.
C
ir
cu
it
b
r
ea
k
er
is
u
s
ed
as
a
s
ep
ar
atio
n
d
ev
ice
at
PC
C
(
s
ec
tio
n
2
.
2
)
.
Pr
o
ce
d
u
r
es
f
o
r
s
elec
tio
n
o
f
r
atin
g
o
f
AC
an
d
DC
s
witch
es
ar
e
n
o
t
s
am
e
-
d
u
e
t
o
h
i
g
h
er
tim
e
co
n
s
tan
t
DC
m
icr
o
r
id
s
n
ee
d
f
ast
ac
tin
g
p
o
wer
elec
tr
o
n
ic
s
witch
es,
s
u
ch
as
G
T
Os,
I
GB
T
s
,
an
d
in
s
u
lated
-
g
a
te
co
m
m
u
tated
th
y
r
is
to
r
s
(
I
GC
T
s
)
,
wh
ich
p
r
ev
en
t
m
eltd
o
wn
o
f
f
u
s
e
i.e
.
,
in
cr
ea
s
e
f
u
s
e
-
s
av
in
g
[
4
]
,
[
7
4
]
.
Su
c
h
d
e
v
ices
h
av
e
d
if
f
e
r
en
t
c
h
ar
ac
ter
is
tics
,
b
u
t
th
e
s
o
lid
-
s
tate
C
B
s
n
ee
d
s
to
b
e
b
i
d
ir
ec
tio
n
al
to
allo
w
p
o
wer
f
lo
w
in
eith
er
d
ir
ec
tio
n
[
7
5
]
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t J Ad
v
Ap
p
l Sci
I
SS
N:
2
2
5
2
-
8
8
1
4
R
ev
iew
o
f p
r
o
tectio
n
a
s
p
ec
ts
o
f m
icro
g
r
id
d
ev
ices
(
A
s
h
o
ke
K
u
ma
r
B
a
s
u
)
219
Fig
u
r
e
3
.
Mic
r
o
g
r
id
l
a
y
o
u
t
-
R
: r
ec
lo
s
er
s
,
S:
s
ec
tio
n
alize
r
s
,
F:
f
u
s
e,
T
:
t
r
an
s
f
o
r
m
er
T
h
e
p
r
o
tectio
n
s
y
s
tem
p
r
e
d
o
m
in
an
tly
u
s
es
r
ec
lo
s
er
s
,
f
u
s
es,
r
elay
s
,
s
ec
tio
n
alis
er
s
,
s
ee
Fig
u
r
e
3
.
I
m
p
o
r
ta
n
ce
o
f
r
ec
lo
s
er
s
ar
is
e
s
as
8
0
%
o
f
f
au
lts
in
d
is
tr
ib
u
tio
n
s
y
s
tem
ar
e
tem
p
o
r
ar
y
[
7
6
]
.
C
o
o
r
d
i
n
atio
n
am
o
n
g
th
ese
d
e
v
ices
is
v
er
y
im
p
o
r
tan
t
f
o
r
p
r
o
tectio
n
.
R
ec
lo
s
er
s
ar
e
p
lace
d
o
n
m
ain
f
ee
d
er
an
d
ac
t
in
co
o
r
d
i
n
atio
n
with
f
u
s
e
o
n
late
r
als
[
1
1
]
.
T
h
e
m
icr
o
p
r
o
ce
s
s
o
r
-
b
ased
r
ec
lo
s
er
s
h
a
v
e
d
ir
ec
tio
n
al
p
r
o
p
e
r
ty
a
n
d
ca
n
s
u
p
p
o
r
t
in
c
o
o
r
d
in
atio
n
.
Sy
n
c
h
r
o
n
izin
g
p
r
o
b
lem
is
s
o
lv
e
d
b
y
d
is
co
n
n
ec
tin
g
all
d
o
wn
s
tr
ea
m
DGs.
Pro
b
lem
s
in
co
o
r
d
in
atio
n
,
also
,
ar
is
e
d
u
e
to
h
ig
h
p
e
n
etr
at
io
n
o
f
DG
s
.
C
ir
cu
it
b
r
ea
k
er
s
,
in
cl
u
d
in
g
r
ec
lo
s
er
s
,
n
ee
d
in
co
r
p
o
r
atio
n
o
f
ch
ec
k
-
s
y
n
ch
r
o
n
izin
g
f
u
n
ctio
n
to
p
er
f
o
r
m
it
s
clo
s
in
g
.
As
p
er
Au
s
tr
alian
S
tan
d
ar
d
4
7
7
7
.
3
an
d
I
E
E
E
Stan
d
ar
d
1
5
4
7
,
th
e
m
ax
i
m
u
m
allo
wab
le
tim
e
f
o
r
o
p
er
a
tio
n
o
f
DG’
s
p
ass
iv
e
an
ti
-
is
lan
d
in
g
p
r
o
tectio
n
is
,
u
s
u
ally
,
two
s
ec
o
n
d
s
[
3
0
]
,
[
3
1
]
.
W
h
er
ea
s
r
ec
lo
s
er
s
r
e
m
ain
o
p
en
i
n
th
e
r
an
g
e
o
f
h
u
n
d
r
e
d
s
o
f
m
illi
s
ec
o
n
d
s
u
p
to
s
ec
o
n
d
s
.
Sy
s
tem
atic
is
lan
d
i
n
g
o
f
m
icr
o
g
r
id
is
n
ec
ess
ar
ily
to
b
e
d
o
n
e
af
ter
s
h
u
ttin
g
-
o
f
f
o
f
all
DG
u
n
its
an
d
it
is
en
s
u
r
ed
b
y
an
ti
-
i
s
lan
d
in
g
p
r
o
tectio
n
.
R
ec
lo
s
in
g
o
f
r
ec
lo
s
er
s
is
s
u
g
g
ested
at
th
e
tim
e
o
f
o
u
t
-
of
-
s
er
v
ice
o
f
all
DG
u
n
its
an
d
th
is
wil
l
eli
m
in
ate
all
p
o
s
s
ib
ilit
ies
o
f
d
am
ag
es
d
u
e
to
u
n
s
y
n
ch
r
o
n
ized
clo
s
in
g
o
f
r
ec
lo
s
er
s
.
Hen
ce
it
is
d
esira
b
le
to
s
elec
t
r
ec
lo
s
er
tim
e
with
co
n
s
i
d
er
ati
o
n
o
f
DG
u
n
it'
s
an
ti
-
is
lan
d
in
g
p
r
o
tectio
n
.
Un
lik
e
r
ec
lo
s
er
s
,
s
ec
tio
n
alize
r
s
co
u
ld
n
o
t
ex
tin
g
u
is
h
th
e
f
a
u
lt
cu
r
r
e
n
t,
wh
ich
is
ass
o
ciate
d
with
its
zo
n
e
o
f
p
r
o
tectio
n
.
Sectio
n
alis
er
s
wo
r
k
in
co
o
r
d
in
atio
n
with
r
ec
lo
s
er
s
.
Sectio
n
alize
r
s
will
o
p
en
af
ter
o
p
en
in
g
o
f
a
n
u
m
b
er
o
f
id
en
tifie
d
r
ec
lo
s
er
s
an
d
an
u
p
s
tr
ea
m
cir
cu
it b
r
ea
k
er
ex
tin
ct
t
h
e
f
au
lt c
u
r
r
en
t [
3
0
]
.
2
.
6
.
Co
m
m
un
ica
t
io
n
dev
ices
T
h
er
e
ar
e
two
co
n
c
ep
ts
o
f
co
m
m
u
n
icatio
n
ar
c
h
itectu
r
es
-
ce
n
tr
alize
d
an
d
d
e
-
ce
n
tr
alize
d
.
I
n
th
e
ce
n
tr
al
co
m
m
u
n
icatio
n
s
y
s
tem
if
co
m
p
u
ter
f
ails
,
th
e
p
r
o
tectio
n
f
o
r
th
e
en
tire
d
is
tr
ib
u
tio
n
s
y
s
tem
will
b
e
d
is
ab
le,
b
u
t
th
e
d
e
-
ce
n
tr
alize
d
s
y
s
tem
h
as
an
ed
g
e
o
v
e
r
it
-
with
th
e
f
ailu
r
e
o
f
o
n
e
n
o
d
e,
p
o
r
tio
n
lo
ca
liz
ed
th
e
n
o
d
e
o
f
th
e
d
is
tr
ib
u
ted
n
etwo
r
k
will
b
e
a
f
f
ec
ted
.
T
h
e
ce
n
tr
alize
d
s
ch
e
m
e
n
ee
d
s
m
o
r
e
co
m
m
u
n
icati
o
n
lin
k
s
an
d
h
e
n
ce
co
s
ts
m
o
r
e.
T
h
e
f
u
lly
d
e
-
ce
n
t
r
alize
d
s
y
s
tem
h
as
th
e
d
r
awb
a
ck
s
th
at
it
h
an
d
les
lo
ca
l
in
f
o
r
m
atio
n
,
n
o
t
ac
ts
o
n
s
y
s
tem
-
wid
e
co
-
o
r
d
i
n
atio
n
.
T
h
e
m
icr
o
g
r
id
s
p
an
s
,
u
s
u
ally
,
a
s
m
all
ar
ea
an
d
th
e
c
o
m
m
u
n
i
ca
tio
n
s
y
s
tem
s
ar
e,
g
en
er
ally
,
u
s
ed
eith
er
o
f
p
il
o
t
wir
es,
o
p
tical
f
i
b
er
s
o
r
t
h
e
e
th
er
n
et.
A
co
m
m
u
n
icati
o
n
-
b
ased
p
r
o
tectio
n
s
ch
em
es
r
eq
u
ir
es
a
ce
n
tr
al
co
n
tr
o
l
u
n
it,
m
ea
s
u
r
em
e
n
t
d
ev
ices
an
d
cir
cu
it
b
r
ea
k
e
r
s
-
all
ar
e
lin
k
ed
v
ia
co
m
m
u
n
icat
io
n
n
etwo
r
k
s
(
s
h
o
wn
in
Fig
u
r
e
.
1
)
.
Mic
r
o
p
r
o
c
ess
o
r
r
elay
f
o
r
MV
m
ic
r
o
g
r
i
d
s
in
ter
co
n
n
ec
ts
a
m
icr
o
g
r
id
ce
n
tr
al
p
r
o
tectio
n
u
n
it
(
C
PU)
an
d
th
e
in
d
iv
i
d
u
a
l
r
elay
s
at
ea
c
h
s
u
b
s
ec
tio
n
v
i
a
a
co
m
m
u
n
icatio
n
n
etwo
r
k
.
An
o
p
tical
e
th
er
n
et
co
m
m
u
n
icatio
n
n
etwo
r
k
is
p
r
o
p
o
s
ed
b
y
r
esear
ch
er
s
in
r
ad
ial
g
r
id
-
c
o
n
n
ec
ted
m
icr
o
g
r
id
t
o
in
teg
r
ate
a
p
r
o
te
ctio
n
an
d
c
o
n
tr
o
l
(
I
PC
)
u
n
it
to
th
e
m
ea
s
u
r
em
e
n
t
d
ev
ices,
c
ir
cu
it
b
r
ea
k
er
s
an
d
co
n
tr
o
l
u
n
its
at
ea
ch
b
u
s
[
3
9
]
,
[
72
]
,
[
78
]
,
[
7
9
]
.
W
ir
eless
m
o
b
ile
b
r
o
a
d
b
an
d
is
p
r
o
p
o
s
ed
i
n
wo
r
k
s
[
7
2
]
,
[
8
0
]
wh
er
e
th
is
co
m
m
u
n
icatio
n
s
y
s
tem
is
u
s
ed
to
co
n
n
ec
t
I
E
Ds
an
d
ci
r
cu
it
b
r
e
ak
er
s
at
ea
c
h
b
u
s
to
th
e
co
n
tr
o
l
ce
n
tr
e.
I
E
Ds
ar
e,
also
,
p
r
o
p
o
s
ed
to
d
etec
t
an
d
lo
ca
te
a
f
au
lt
in
th
e
d
is
tr
ib
u
tio
n
n
etwo
r
k
a
n
d
to
f
ac
ilit
ate
th
e
d
ata
co
m
m
u
n
icatio
n
s
to
a
ce
n
tr
al
co
m
p
u
t
er
.
Alg
o
r
ith
m
is
to
b
e
f
r
a
m
ed
to
i
d
en
tify
t
h
e
ap
p
r
o
p
r
iate
cir
cu
it
b
r
ea
k
er
s
to
tr
ip
an
d
clea
r
th
e
f
au
lt.
Alg
o
r
ith
m
d
e
p
en
d
s
o
n
th
e
cu
r
r
e
n
t,
v
o
ltag
e
a
n
d
d
ir
ec
tio
n
al
s
ig
n
als
r
ec
eiv
e
d
f
r
o
m
r
em
o
te
I
E
Ds
to
g
en
e
r
ate
tr
ip
o
r
b
lo
c
k
s
ig
n
als
th
at
ar
e
s
en
t
b
ac
k
to
t
h
e
I
E
Ds
v
ia
t
h
e
f
au
lted
p
ath
[
1
1
]
,
[
26
]
,
[
81
]
,
[
8
2
]
.
T
h
e
ce
n
tr
al
co
m
p
u
ter
is
a
p
ar
t
o
f
ce
n
tr
al
p
r
o
tectio
n
u
n
it
(
C
PU)
,
wh
ich
is
ag
ain
a
p
ar
t
o
f
MG
C
C
lo
ca
ted
at
PC
C
.
C
en
tr
al
co
m
p
u
ter
wo
r
k
s
as
:
i)
r
e
ce
iv
in
g
o
f
in
f
o
r
m
atio
n
a
b
o
u
t
th
e
n
etwo
r
k
to
p
o
lo
g
y
/co
n
f
i
g
u
r
atio
n
an
d
D
G
s
tatu
s
(
wh
eth
er
c
o
n
n
ec
tio
n
s
o
r
d
is
co
n
n
ec
tio
n
s
)
,
ii)
ac
co
r
d
in
g
ly
,
th
e
s
ettin
g
s
o
f
th
e
p
r
o
tect
io
n
d
e
v
ices
b
ein
g
ad
ju
s
ted
,
an
d
iii)
last
ly
m
ain
tain
co
o
r
d
in
atio
n
b
etwe
en
th
e
d
ev
ices
[
1
1
]
,
[
82
]
,
[
8
6
]
.
T
h
e
ce
n
tr
alize
d
s
ch
em
e
is
im
p
lem
en
ted
with
s
er
ial/b
u
s
co
m
m
u
n
icatio
n
an
d
u
s
e
p
o
wer
-
lin
e
ca
r
r
ier
o
r
Evaluation Warning : The document was created with Spire.PDF for Python.
I
SS
N
:
2
2
5
2
-
8
8
1
4
I
n
t J Ad
v
Ap
p
l Sci
,
Vo
l.
10
,
No
.
3
,
Sep
tem
b
er
2
0
2
1
:
21
2
–
22
6
220
E
th
er
n
et
n
etwo
r
k
.
T
h
e
co
m
m
u
n
icatio
n
p
r
o
to
co
ls
u
s
ed
ar
e
Mo
d
b
u
s
,
DNP3
,
I
E
C
6
0
8
7
0
-
5
-
1
0
1
/1
0
4
,
an
d
I
E
C
6
1
8
5
0
.
On
th
e
o
th
er
h
a
n
d
,
d
e
ce
n
tr
alize
d
co
n
tr
o
l
r
elies
o
n
i
n
f
o
r
m
atio
n
ex
ch
an
g
e
b
etwe
en
I
E
Ds
an
d
u
s
e
I
E
C
6
1
8
5
0
p
r
o
t
o
co
ls
f
o
r
d
ec
en
tr
alize
d
co
m
m
u
n
icatio
n
.
T
h
e
alg
o
r
ith
m
r
eq
u
ir
es
to
s
u
it
r
ea
l
-
tim
e
two
-
way
co
m
m
u
n
icatio
n
an
d
d
e
f
en
d
s
cy
b
er
attac
k
s
.
T
h
e
alg
o
r
ith
m
is
b
ased
o
n
co
m
m
u
n
icatio
n
in
f
r
astru
ctu
r
e
an
d
esti
m
atio
n
.
T
h
e
r
esear
ch
er
s
h
av
e
ad
d
r
ess
ed
lo
s
s
-
of
-
m
ai
n
s
d
etec
tio
n
,
d
if
f
er
e
n
tial
p
r
o
tec
tio
n
u
s
in
g
s
y
s
tem
s
with
co
m
m
u
n
icatio
n
n
etwo
r
k
s
.
T
h
e
r
esear
ch
er
s
h
av
e
ta
k
en
c
h
allen
g
e
o
f
lo
s
s
-
of
-
m
ain
s
d
ete
ctio
n
u
s
in
g
p
h
aso
r
m
ea
s
u
r
em
en
t
u
n
its
(
PMUs)
a
n
d
g
lo
b
al
p
o
s
itio
n
in
g
s
y
s
tem
(
GPS)
an
d
d
if
f
er
en
tial
p
r
o
tecti
o
n
with
I
E
Ds
u
s
i
ng
class
if
ier
as
s
is
ted
b
y
co
m
m
u
n
icatio
n
n
etwo
r
k
s
b
ased
o
n
t
h
e
I
E
C
6
1
8
5
0
s
er
v
ice
tr
ac
k
in
g
m
ec
h
an
is
m
[
1
1
]
,
[
19
]
,
[
39
]
,
[
87
]
-
[
9
4
]
.
2
.
7
.
O
t
her
Dev
ices
2
.
7
.
1
.
F
a
ult
curr
ent
lim
it
er
s
(
F
CL
s
)
FC
L
is
p
lace
d
n
ea
r
th
e
PC
C
,
s
ee
Fig
u
r
e
1
.
FC
L
lim
its
th
e
f
au
lt
cu
r
r
en
t (
s
h
o
r
t
-
cir
c
u
it)
lev
el
-
wh
eth
er
f
au
lt
cu
r
r
en
t f
r
o
m
th
e
m
ain
g
r
i
d
to
th
e
m
icr
o
g
r
id
o
r
b
y
th
e
D
Gs
(
s
y
n
ch
r
o
n
o
u
s
-
b
ased
d
is
tr
ib
u
ted
g
e
n
er
ato
r
s
)
in
th
e
m
icr
o
g
r
id
to
war
d
s
th
e
m
ain
g
r
id
.
Ad
v
an
ta
g
es
o
f
th
e
FC
L
s
co
u
ld
,
n
am
ely
,
b
e
f
o
llo
wed
to
:
‘
n
o
DG
d
is
co
n
n
ec
tio
n
’
,
‘
n
o
u
p
-
g
r
ad
at
io
n
o
f
r
elay
s
ettin
g
s
’
,
‘
n
o
u
p
-
g
r
ad
atio
n
o
f
d
ev
ices
f
o
r
h
an
d
lin
g
h
ig
h
cu
r
r
en
ts
.
B
u
t
im
p
ed
an
ce
o
f
FC
L
in
cr
ea
s
es
wi
th
in
cr
ea
s
e
in
in
d
iv
id
u
al
DG
ca
p
ac
ity
h
en
ce
its
co
s
t
in
cr
ea
s
es.
Mo
r
eo
v
er
,
tr
an
s
ien
t
r
esp
o
n
s
e
o
f
FC
L
is
an
o
th
er
co
n
ce
r
n
[
1
8
]
.
T
h
er
e
a
r
e
th
r
ee
ty
p
es
o
f
FC
L
,
n
am
el
y
,
s
u
p
er
co
n
d
u
ctin
g
FC
L
,
s
o
lid
s
tate
FC
L
,
elec
tr
o
m
ag
n
etic
FC
L
[
4
]
,
[
36
]
,
[
39
]
,
[
9
5
]
.
I
m
p
ac
t
o
f
DG,
if
n
eg
ativ
e,
is
to
b
e
m
in
im
ized
b
y
p
lacin
g
FC
L
,
s
ee
Fig
u
r
e
1
o
n
th
e
DG
b
r
an
ch
an
d
o
v
er
cu
r
r
e
n
t
r
elay
s
o
p
er
a
tes
at
s
ig
n
if
ican
tly
r
ed
u
ce
d
tim
e
[
4
]
,
[
96
]
,
[
9
7
]
.
FC
L
b
ec
o
m
es
a
p
ar
t
o
f
a
C
en
tr
al
Pro
tectio
n
Un
it
(
C
PU)
an
d
a
co
m
m
u
n
icatio
n
s
y
s
tem
-
to
m
o
n
ito
r
th
e
s
tatu
s
o
f
m
icr
o
g
r
id
,
to
p
r
ed
ict
f
a
u
lt
co
n
d
itio
n
s
,
to
p
r
o
g
r
am
th
e
p
r
o
tectio
n
s
y
s
tem
an
d
u
p
d
ate
tr
i
p
v
alu
e
o
f
r
elay
s
[
4
]
,
[
39
]
,
[
4
0
]
.
C
-
DG
u
s
es
th
e
p
r
o
tectio
n
s
ch
em
e
with
an
F
C
L
to
en
s
u
r
e
f
au
lt
d
etec
tio
n
with
o
u
t
s
u
r
p
ass
in
g
cu
r
r
en
t
r
atin
g
s
[
3
0
]
,
[
4
7
]
.
T
h
y
r
is
to
r
-
co
n
tr
o
lled
s
er
ies
ca
p
a
cito
r
(
T
C
SC
)
ty
p
e
FC
L
is
co
n
n
ec
ted
in
s
er
ies
wi
th
DG
u
n
it
f
o
r
o
n
ly
g
r
id
-
co
n
n
ec
ted
m
o
d
e
to
lim
it
DG
s
h
ar
in
g
o
f
f
a
u
lt
cu
r
r
e
n
t
[
9
8
]
-
[
1
0
0
]
.
T
h
e
tie
f
ee
d
er
c
o
n
n
ec
ts
u
p
s
tr
ea
m
an
d
d
o
wn
s
tr
ea
m
n
etwo
r
k
s
-
th
er
e
is
a
lo
s
s
o
f
co
o
r
d
in
atio
n
b
etwe
en
th
e
u
p
s
tr
ea
m
an
d
d
o
wn
s
tr
ea
m
p
r
o
tectiv
e
r
elay
s
.
T
o
o
v
er
c
o
m
e
th
is
p
r
o
b
le
m
,
co
n
v
en
tio
n
al
b
i
-
d
ir
ec
tio
n
al
FC
L
s
is
r
ep
lace
d
b
y
u
n
id
ir
ec
tio
n
al
f
au
lt c
u
r
r
en
t li
m
iter
(
UFC
L
)
[
1
0
1
]
,
[
1
0
2
]
.
2
.
7
.
2
.
G
ro
un
din
g
I
n
th
e
d
is
tr
ib
u
tio
n
n
etwo
r
k
,
9
8
%
f
au
lts
ar
e
g
r
o
u
n
d
f
au
lts
.
Op
er
atin
g
p
r
i
n
cip
le
o
f
f
au
lt
p
r
o
tectio
n
s
y
s
tem
s
o
f
m
icr
o
g
r
id
is
d
ep
e
n
d
en
t
o
n
its
g
r
o
u
n
d
in
g
co
n
f
ig
u
r
atio
n
s
:
m
u
lti
-
g
r
o
u
n
d
in
g
,
u
n
i
-
g
r
o
u
n
d
in
g
an
d
u
n
-
g
r
o
u
n
d
in
g
[
3
6
]
.
T
h
e
o
u
tco
m
e
o
f
th
e
r
esear
ch
in
f
o
r
m
e
d
th
at
T
N
-
S
s
y
s
tem
o
f
g
r
o
u
n
d
in
g
s
o
lv
e
th
e
p
r
o
b
lem
o
f
d
etec
tio
n
o
f
f
a
u
lt
cu
r
r
e
n
t
in
is
lan
d
in
g
m
o
d
e
with
C
-
DG
r
eso
u
r
ce
s
.
W
h
er
ea
s
with
T
T
an
d
I
T
s
y
s
tem
s
,
p
r
o
tectiv
e
r
elay
s
co
u
ld
n
o
t
d
is
tin
g
u
is
h
b
etwe
en
f
au
lt
c
u
r
r
en
t
a
n
d
l
o
ad
c
u
r
r
e
n
t
o
f
t
h
e
m
icr
o
g
r
id
.
T
o
co
m
p
r
o
m
is
e
b
etwe
en
th
e
o
v
er
-
v
o
ltag
e
lim
it
an
d
th
e
r
ea
s
o
n
ab
le
f
au
lt
-
cu
r
r
en
t,
p
r
o
p
er
g
r
o
u
n
d
in
g
im
p
ed
a
n
ce
will b
e
s
elec
ted
[
2
]
,
[
4
]
,
[
103
]
,
[
1
0
4
]
.
DC
m
icr
o
g
r
id
is
in
f
lu
en
ce
d
b
y
g
r
o
u
n
d
in
g
s
ch
em
e
,
b
o
th
th
e
tr
an
s
ien
t
s
h
o
r
t
cir
cu
it
c
u
r
r
en
t
an
d
o
v
er
v
o
ltag
e
o
f
th
e
DC
m
icr
o
g
r
id
ar
e
h
i
g
h
ly
af
f
ec
ted
.
Fau
l
t
d
etec
tio
n
an
d
p
r
o
tectio
n
ca
p
ab
ilit
ies
ar
e
b
ad
ly
ch
an
g
ed
.
A
s
in
g
le
p
o
le
g
r
o
u
n
d
f
au
lt
in
an
u
n
g
r
o
u
n
d
ed
(
f
lo
a
tin
g
)
DC
m
icr
o
g
r
id
p
r
o
d
u
ce
s
lo
w
g
r
o
u
n
d
cu
r
r
en
t
an
d
it
is
v
er
y
d
if
f
icu
lt
t
o
d
etec
t
an
d
lo
ca
te
b
y
d
if
f
e
r
en
t
d
etec
to
r
s
[
2
]
,
[
1
0
4
]
-
[
1
0
6
]
.
Ag
ai
n
,
r
esis
tan
ce
g
r
o
u
n
d
ed
s
y
s
tem
p
r
o
d
u
ce
s
a
s
m
all
c
u
r
r
e
n
t
an
d
r
e
d
u
ce
d
v
o
ltag
e
tr
an
s
ie
n
t
d
u
r
in
g
a
s
in
g
le
p
o
le
g
r
o
u
n
d
f
au
lt
.
H
en
ce
,
l
o
ad
s
ar
e
s
u
p
p
lied
c
o
n
tin
u
o
u
s
ly
with
o
u
t
in
ter
r
u
p
tio
n
.
I
f
th
e
s
y
s
tem
is
s
o
lid
ly
g
r
o
u
n
d
e
d
,
th
en
f
au
lt
co
u
ld
ea
s
ily
be
d
etec
ted
an
d
q
u
ick
ly
clea
r
ed
.
[2
]
,
[
1
0
5
]
-
[
1
0
8
]
.
3.
CO
NCLU
SI
O
N
Mic
r
o
g
r
id
is
p
o
is
ed
f
o
r
m
o
r
e
p
o
s
itiv
e
g
r
o
wth
in
th
e
r
ec
en
t
f
u
tu
r
e
o
f
d
er
e
g
u
lated
r
eg
im
e.
Mo
r
e
r
esear
ch
is
af
o
o
t
all
o
v
er
t
h
e
wo
r
ld
t
o
u
s
h
e
r
a
r
eliab
le
f
o
r
m
o
f
m
icr
o
g
r
id
.
Pro
tectio
n
is
a
m
o
s
t
v
u
ln
er
a
b
le
asp
ec
t
o
f
m
icr
o
g
r
id
o
p
er
atio
n
an
d
n
ee
d
s
a
s
p
ec
ial
atten
tio
n
f
o
r
u
n
i
n
ter
r
u
p
ted
/o
r
m
in
im
u
m
in
ter
r
u
p
tio
n
in
th
e
o
p
er
atio
n
o
f
m
icr
o
g
r
id
.
T
h
e
p
r
esen
t
r
ev
iew
is
f
o
c
u
s
ed
o
n
th
e
co
n
s
titu
en
t
d
ev
ices
o
f
th
e
m
icr
o
g
r
id
.
T
h
e
p
r
esen
t
r
ev
iew
wo
r
k
ad
d
r
ess
es
th
e
r
esear
ch
e
r
s
’
wo
r
k
s
in
co
n
n
ec
tio
n
with
th
e
p
r
o
tectio
n
asp
ec
ts
o
f
th
ese
d
ev
ices.
I
n
b
o
th
n
o
r
m
al
an
d
is
lan
d
in
g
m
o
d
es,
th
e
p
r
esen
ce
o
f
DG
u
n
its
ch
an
g
es th
e
o
p
er
atio
n
o
f
a
m
icr
o
g
r
id
–
s
u
ch
as
ch
an
g
e
o
f
f
au
lt
cu
r
r
en
t
lev
el,
f
alse
tr
ip
p
i
n
g
,
b
lin
d
n
ess
o
f
p
r
o
tectio
n
,
p
r
o
h
ib
itio
n
o
f
au
to
m
atic
r
ec
lo
s
in
g
,
an
d
u
n
s
y
n
ch
r
o
n
ize
d
r
ec
lo
s
in
g
.
An
ap
p
r
o
p
r
iate
p
r
o
tectio
n
s
y
s
tem
f
o
r
m
icr
o
g
r
id
s
r
eq
u
ir
es
p
r
o
p
er
co
n
s
id
er
atio
n
s
o
n
th
e
k
ey
f
ac
t
o
r
s
,
m
ain
ly
o
n
c
h
ar
ac
ter
is
tics
,
co
n
s
tr
u
ctio
n
,
o
f
m
ic
r
o
g
r
id
d
e
v
ices
s
u
ch
as
f
ee
d
er
an
d
to
p
o
lo
g
y
,
DGs
an
d
tr
an
s
f
o
r
m
er
s
,
co
m
m
u
n
icatio
n
s
y
s
tem
,
to
n
am
e
a
f
ew
f
r
o
m
th
e
s
ec
tio
n
2
.
A
co
m
p
r
eh
e
n
s
iv
e
r
ev
iew
o
n
t
h
e
v
ar
io
u
s
p
r
o
tectio
n
p
lan
s
o
f
t
h
ese
d
ev
ices
h
as
b
ee
n
p
er
f
o
r
m
ed
b
ased
o
n
t
h
e
Evaluation Warning : The document was created with Spire.PDF for Python.
I
n
t J Ad
v
Ap
p
l Sci
I
SS
N:
2
2
5
2
-
8
8
1
4
R
ev
iew
o
f p
r
o
tectio
n
a
s
p
ec
ts
o
f m
icro
g
r
id
d
ev
ices
(
A
s
h
o
ke
K
u
ma
r
B
a
s
u
)
221
p
r
o
p
o
s
al
b
y
p
r
ev
io
u
s
au
th
o
r
s
.
T
h
e
p
r
o
tectio
n
s
tr
ateg
ies
h
av
e
b
ee
n
p
r
o
p
o
s
ed
b
y
th
e
r
esear
c
h
er
s
to
ex
ten
d
to
a
g
en
er
al
d
is
tr
ib
u
tio
n
s
y
s
tem
with
m
u
ltip
le
ty
p
es
o
f
DGs,
d
if
f
er
en
t
s
t
r
u
ctu
r
es
o
r
to
p
o
lo
g
ies
o
f
n
etwo
r
k
s
,
alg
o
r
ith
m
with
m
in
im
u
m
co
m
m
u
n
icatio
n
r
eq
u
ir
em
e
n
ts
,
p
r
o
tectio
n
ag
ain
s
t
cy
b
er
attac
k
s
an
d
less
im
p
ac
t
o
f
co
m
m
u
n
icatio
n
lin
k
f
ailu
r
e.
P
r
o
tectio
n
co
o
r
d
in
atio
n
s
tr
ateg
y
o
p
er
ates
f
aster
with
co
m
m
u
n
icatio
n
n
etwo
r
k
in
g
.
T
h
e
ef
f
ec
ts
o
f
FC
L
an
d
g
r
o
u
n
d
in
g
/u
n
-
g
r
o
u
n
d
i
n
g
o
n
m
icr
o
g
r
id
p
r
o
tectio
n
h
av
e
also
b
ee
n
r
e
v
iewe
d
.
RE
F
E
R
E
NC
E
S
[1
]
TS
.
Us
tu
n
,
Ca
g
il
Oz
a
n
so
y
a
n
d
A
lad
in
Zay
e
g
h
,
"
Re
c
e
n
t
d
e
v
e
l
o
p
m
e
n
ts
in
m
icr
o
g
ri
d
s
a
n
d
e
x
a
m
p
le
c
a
se
s
a
ro
u
n
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e
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Rev
iews
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[2
]
D.
S
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P
ro
tec
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Lo
w
-
Vo
lt
a
g
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DC
M
icro
g
ri
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s,"
i
n
IEE
E
T
ra
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WRD.
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2
.
[3
]
S
.
Ch
a
k
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ty
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.
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.
S
imo
e
s,
"
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x
p
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rime
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teri
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M
icro
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n
IEE
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T
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EC.
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0
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8
.
[4
]
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.
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.
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ss
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i
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.
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Ab
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.
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h
i
,
F.
Ra
z
a
v
i,
A
.
Na
siri
,
"
An
o
v
e
rv
iew
o
f
m
icro
g
rid
p
ro
tec
ti
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n
m
e
th
o
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s
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th
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fa
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to
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o
l
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d
,
"
Ren
e
wa
b
le
a
n
d
S
u
st
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i
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a
b
le
E
n
e
rg
y
Rev
iews
,
v
o
l.
64
,
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p
.
1
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–
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0
8
9
.
[5
]
S.
Ch
e
n
,
N
.
Tai,
C.
F
a
n
,
J.
Li
u
,
S
.
Ho
n
g
,
"
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e
q
u
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e
-
c
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m
p
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-
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se
d
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iffere
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p
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tec
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r
tran
sm
issio
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ted
wit
h
IIG
s
,
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Ge
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e
r.
T
r
a
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sm
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trib
.
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[6
]
S
.
P
a
rh
izi,
H.
L
o
tfi
,
A.
Kh
o
d
a
e
i
a
n
d
S
.
Ba
h
ra
m
irad
,
"
S
tate
o
f
t
h
e
Art
in
Re
se
a
rc
h
o
n
M
icro
g
rid
s:
A
Re
v
iew
,
"
i
n
IEE
E
Acc
e
ss
,
v
o
l
.
3
,
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p
.
8
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9
2
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5
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/ACCES
S
.
2
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5
.
2
4
4
3
1
1
9
.
[7
]
S.
Ch
o
wd
h
u
r
y
,
S
P
.
Ch
o
wd
h
u
r
y
,
P
.
Cro
ss
ley
,
M
icr
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rid
s
a
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Active
Distrib
u
ti
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Ne
two
rk
s
.
In
stit
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IE
T
Dig
it
a
l
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ra
ry
:
UK
,
2
0
0
9
.
[8
]
R.
Nd
o
u
,
J.
I.
F
a
d
iran
,
S
.
Ch
o
wd
h
u
ry
a
n
d
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.
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.
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wd
h
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r
y
,
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e
rfo
rm
a
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p
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lt
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q
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r
m
icro
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rid
s,
"
2
0
1
3
I
EE
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.
6
6
7
2
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8
8
.
[9
]
S
.
L
iu
,
T.
Bi,
A.
Xu
e
a
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d
Q.
Ya
n
g
,
"
F
a
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ly
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iffere
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istri
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2
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IE
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.
2
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0
3
9
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.
[1
0
]
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Je
n
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tt
,
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.
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ffe
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a
n
d
C.
Bo
o
th
,
"
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o
m
p
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v
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n
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q
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ly
sis
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ro
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s
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ss
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c
iate
d
with
in
c
re
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trati
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f
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v
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rter
-
in
terfa
c
e
d
DG
,
"
1
1
th
IE
T
In
ter
n
a
ti
o
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a
l
Co
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fer
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o
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De
v
e
lo
p
me
n
ts
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Po
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r S
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ms
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(DPS
P
2
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)
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p
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.
[1
1
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P
.
T.
M
a
n
d
it
e
re
z
a
a
n
d
R.
Ba
n
sa
l
,
"
Re
n
e
wa
b
le
d
istr
ib
u
ted
g
e
n
e
ra
ti
o
n
:
Th
e
h
id
d
e
n
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h
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ll
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n
g
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s
-
A
re
v
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fro
m
th
e
p
ro
tec
ti
o
n
p
e
rsp
e
c
ti
v
e
,
"
Ren
e
w
a
b
le
a
n
d
S
u
sta
i
n
a
b
le
E
n
e
rg
y
Rev
iews
,
v
o
l.
58
,
p
p
.
1
4
5
7
–
1
4
6
5
,
2
0
1
6
,
d
o
i:
1
0
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1
0
1
6
/
j.
rse
r.
2
0
1
5
.
1
2
.
2
7
6
.
[1
2
]
D.
M
.
B
u
i
,
S
.
L.
Ch
e
n
,
K.
Y.
L
ien
,
Y.
R.
Ch
a
n
g
,
Y.
D.
Lee
,
a
n
d
J.
L.
Jia
n
g
,
"
I
n
v
e
sti
g
a
ti
o
n
o
n
tra
n
si
e
n
t
b
e
h
a
v
io
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rs
o
f
a
u
n
i
-
g
r
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u
n
d
e
d
l
o
w
-
v
o
lt
a
g
e
A
C
m
icro
g
ri
d
a
n
d
e
v
a
lu
a
ti
o
n
o
n
it
s
a
v
a
il
a
b
le
fa
u
lt
p
r
o
tec
ti
o
n
m
e
th
o
d
s:
Re
v
iew
a
n
d
p
ro
p
o
sa
ls
,
"
Ren
e
wa
b
le
a
n
d
S
u
st
a
in
a
b
le
En
e
rg
y
Rev
iews
,
v
o
l.
75
,
p
p
.
1
4
1
7
–
1
4
5
2
,
2
0
1
7
,
d
o
i:
1
0
.
1
0
1
6
/
j.
rse
r.
2
0
1
6
.
1
1
.
1
3
4
.
[1
3
]
T.
N.
B
o
u
tsi
k
a
a
n
d
S
.
A.
P
a
p
a
t
h
a
n
a
ss
io
u
,
"
S
h
o
rt
-
c
ircu
it
c
a
lcu
latio
n
s
in
n
e
two
r
k
s
wit
h
d
istri
b
u
t
e
d
g
e
n
e
ra
ti
o
n
,
"
El
e
c
tr P
o
we
r S
y
st R
e
s
,
v
o
l.
78
,
n
o
.
7
,
p
p
.
1
1
8
1
–
11
91
,
2
0
0
8
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d
o
i:
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0
1
6
/j
.
e
p
sr.2
0
0
7
.
1
0
.
0
0
3
.
[1
4
]
H.
M
a
rg
o
ss
ian
,
G
.
De
c
o
n
i
n
c
k
a
n
d
J.
S
a
c
h
a
u
,
"
Distrib
u
ti
o
n
n
e
two
r
k
p
r
o
tec
ti
o
n
c
o
n
sid
e
ri
n
g
g
ri
d
c
o
d
e
re
q
u
irem
e
n
ts
fo
r
d
istri
b
u
ted
g
e
n
e
ra
ti
o
n
,
"
IE
T
Ge
n
e
r.
T
ra
n
sm
.
Distrib
.,
vol
.
9
,
no
.
1
2
,
p
p
.
1
3
7
7
–
1
3
8
1
,
2
0
1
5
,
d
o
i:
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0
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1
0
4
9
/i
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t
-
g
td
.
2
0
1
4
.
0
9
8
7
.
[1
5
]
O.
Nú
ñ
e
z
-
M
a
taa
,
R.
P
a
lma
-
Be
h
n
k
e
b
,
F
.
Va
len
c
iab
,
A.
Urru
ti
a
-
M
o
li
n
a
b
,
P
.
M
e
n
d
o
z
a
-
Ara
y
a
b
,
a
n
d
G
.
Jim
é
n
e
z
-
Estév
e
z
b
,
"
C
o
u
p
li
n
g
a
n
a
d
a
p
ti
v
e
p
ro
tec
ti
o
n
sy
ste
m
with
a
n
e
n
e
rg
y
m
a
n
a
g
e
m
e
n
t
sy
ste
m
fo
r
m
icro
g
ri
d
s
,
"
T
h
e
El
e
c
tricity J
o
u
rn
a
l
,
vo
l.
32
,
n
o
.
1
0
,
p
.
1
0
6
6
7
5
,
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0
1
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o
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0
1
6
/j
.
tej.
2
0
1
9
.
1
0
6
6
7
5
.
[1
6
]
M.
Br
u
c
o
li
a
n
d
T.
C.
G
re
e
n
,
"
F
a
u
lt
b
e
h
a
v
i
o
u
r
in
islan
d
e
d
m
icro
g
rid
s
,
"
in
Pro
c
e
e
d
in
g
s
o
f
t
h
e
1
9
t
h
i
n
ter
n
a
ti
o
n
a
l
c
o
n
fer
e
n
c
e
o
n
e
lec
tricity d
istrib
u
t
io
n
,
CIRE
D
,
2
0
0
7
,
p
.
0
5
4
8
.
[1
7
]
I.
K.
Tars
i,
A.
S
h
e
ik
h
o
les
lam
i,
T.
Ba
rfo
ro
u
s
h
i
a
n
d
S
.
M
.
B.
S
a
d
a
ti
,
"
In
v
e
stig
a
ti
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g
imp
a
c
ts
o
f
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istri
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u
ted
g
e
n
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ra
ti
o
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o
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d
istri
b
u
ti
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n
n
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two
rk
s
re
li
a
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il
it
y
:
A
m
a
th
e
m
a
ti
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a
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o
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l,
"
Pro
c
e
e
d
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o
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2
0
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0
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e
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tric
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a
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ly R
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p
.
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o
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/
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Q
.
2
0
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0
.
5
5
5
0
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1
0
.
[1
8
]
L.
K.
Ku
m
p
u
lain
e
n
a
n
d
K.
T.
Ka
u
h
a
n
iem
i,
"
An
a
l
y
sis
o
f
th
e
imp
a
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t
o
f
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istri
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ra
ti
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o
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to
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ti
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re
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sin
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