Internati
o
nal
Journal of P
o
wer Elect
roni
cs an
d
Drive
S
y
ste
m
(I
JPE
D
S)
V
o
l.
6, N
o
. 3
,
Sep
t
em
b
e
r
2015
, pp
. 42
9
~
43
2
I
S
SN
: 208
8-8
6
9
4
4
29
Jo
urn
a
l
h
o
me
pa
ge
: h
ttp
://iaesjo
u
r
na
l.com/
o
n
lin
e/ind
e
x.ph
p
/
IJPEDS
Droop Characteristics of Doubly Fed Induction Generator
Energy Storage Systems within Micro Grids
K.L. Sireesha,
G. Kes
a
va Rao
Departm
e
nt o
f
E
l
ec
tric
al
a
nd
Electronics Engin
e
ering, K
L Univ
er
sity
, Guntur
, Ind
i
a
Article Info
A
B
STRAC
T
Article histo
r
y:
Received Feb 13, 2015
Rev
i
sed
Ju
l 1
,
2
015
Accepte
d
J
u
l 20, 2015
This article presen
ts the oper
a
tio
n of DFIG
Dou
b
ly
f
e
d inductio
n generato
r
and a componen
t
energ
y
storag
e (ES) within micro grids (MG). The aim of
this proposal is
to contro
l voltage a
nd fr
equency
of wind f
a
rm micro grid
shared b
y
th
e Doubly
fed
induction g
e
ner
a
tor (DFIG) th
rough droop
c
h
a
r
ac
te
ri
st
ic
s.
T
h
i
s
pa
pe
r i
s
ma
i
n
ly
concerned
with the operatio
n of islanded
micro grids.
The proposed
control meth
ods are preten
d b
y
using
Matlab/sim
u
link
.
Keyword:
D
oub
ly f
e
d
indu
ctio
n g
e
n
e
r
a
to
r
Droop cha
r
acteristics
Ener
gy
st
ora
g
e
M
i
cro gri
d
s
W
i
n
d
farm
Copyright ©
201
5 Institut
e
o
f
Ad
vanced
Engin
eer
ing and S
c
i
e
nce.
All rights re
se
rve
d
.
Co
rresp
ond
i
ng
Autho
r
:
K.L
.
Siree
s
ha
,
Depa
rt
m
e
nt
of El
ect
ri
cal
and
El
ect
roni
cs
E
n
gi
nee
r
i
n
g, K
L
Uni
v
ersi
t
y
, Gu
nt
u
r
, In
di
a.
Em
a
il: lsirish
a
9
@
g
m
ail.co
m
1.
INTRODUCTION
In
re
newa
bl
e
ener
gy
re
so
urc
e
s,
wi
n
d
i
s
a
n
im
port
a
nt
s
o
urce
f
o
r
h
u
m
a
n
bei
n
g as
t
h
e
re
newa
bl
e
en
erg
y
of p
e
netratio
n
in
creases, th
e
p
r
o
b
l
e
m
s wh
ich
are
m
a
in
ly cau
sed
b
y
th
e i
n
term
i
tten
t
n
a
tu
re of
rene
wa
ble ene
r
gy. T
o
achie
ve this, each
com
pone
nt
m
u
st
react to local inform
ation suc
h
as volt
a
ge and
fre
que
ncy
t
o
c
o
r
r
ect
l
y
chan
g
e
i
t
s
operat
i
o
n
poi
nt
.
It
i
s
also desi
rabl
e t
o
ensu
re t
h
at
n
o
com
pon
ent
(
e
.g.
,
a
master cont
roll
er) is
critical for m
i
cr
o
g
rid op
eration
.
An
effectiv
e
way t
o
ach
iev
e
lo
cal
co
n
t
ro
l
witho
u
t fast-
centralized com
m
unication is to control active and
r
eactive power injection to/
f
rom
each com
pone
nt utilizing
freq
u
e
n
c
y and
v
o
ltag
e
d
r
o
o
p
s
resp
ectiv
ely.
Du
e to th
is
p
r
o
b
l
em
, th
e syste
m
m
a
y lo
se th
eir stab
ility. Th
at’s
wh
y, t
h
e system req
u
i
red
an
en
erg
y
b
a
ck
-up
to
im
p
r
ov
e
th
e stab
ility o
f
t
h
e system
an
d
also
red
u
ce
grid
lo
sses
[1]
.
T
h
e m
i
crog
ri
ds a
r
e an
i
n
t
e
grat
ed e
n
ergy
del
i
v
e
r
y
sy
st
em
. The
m
i
crogri
d
c
o
nsi
s
t
s
of
uni
fi
ed D
G
(di
s
t
r
i
but
e
d
ge
nerat
o
rs
) an
d c
ont
rol
l
a
bl
e l
o
a
d
s. It
o
p
e
r
ates in
p
a
rallel with
th
e m
a
in
p
o
w
er
g
r
id. Micro
g
rids
can
are
u
s
efu
l
to
custo
m
ers by p
r
ov
id
es
un
in
terrup
tib
le
p
o
wer, im
p
r
o
v
i
ng
reliab
ility, red
u
c
i
n
g th
e lo
sses
of
transm
ission a
n
d sustai
ning
local volta
ge and
freque
ncy
[2]. To obtain
this eac
h
DG m
u
st react to local
i
n
f
o
rm
at
i
on
su
ch
as v
o
l
t
a
ge and
f
r
eq
ue
ncy
t
o
pr
ope
rl
y
c
h
an
ge
i
t
s
o
p
er
at
i
ng poi
nt
. A hel
p
ful
way
t
o
at
t
a
i
n
local control without
fast ce
nt
ralized
c
o
m
m
u
n
ication is
to c
ont
rol active
a
n
d reactive
power
injection to/from
each
DG by
utilizing freque
nc
y an
d voltage
droops c
o
rrespondi
ngly.
W
i
nd
en
erg
y
ch
ang
e
with
time an
d
d
i
fficu
lt to
d
e
term
in
e.
Elu
c
id
ation
for th
e in
ter
m
it
te
n
c
y an
d
the
sho
r
t
t
e
rm
changea
b
l
e
nat
u
re
associ
at
ed wi
t
h
wi
n
d
ene
r
gy
gene
rat
i
o
n can
be com
p
ensat
e
d pa
rt
i
a
l
l
y
by usi
n
g
Ener
gy
st
o
r
ag
e
(ES
)
sy
st
em
s. The c
o
m
b
i
n
at
i
on
of t
h
e ES
sy
st
em
i
n
t
o
wi
nd e
n
e
r
gy
gen
e
rat
i
on ca
n
be
very
usef
ul
t
o
t
h
e p
o
we
r sy
st
em
i
n
m
a
ny
way
s
:
such as sm
oot
hi
ng t
h
e
wi
n
d
p
o
w
er
fl
u
c
tu
ations th
roug
h
cap
tiv
ating
its flu
c
tu
atio
n
s
an
d
prov
id
es
activ
e p
o
wer balan
c
in
g, In
or
der t
o
su
p
p
o
r
t
t
h
e l
o
cal
gri
d
f
r
eq
ue
ncy
cont
r
o
l
b
y
p
r
ov
id
ing
sp
inn
i
ng
reserv
e,
an
d th
e l
o
w vo
ltag
e
rid
e
t
h
ro
ugh
cap
a
b
ility b
y
serv
ing
as a po
wer si
n
k
du
ri
n
g
low
syste
m
v
o
ltag
e
[3
-6
].
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
6, No
. 3, Sep
t
em
b
e
r
2
015
:
42
9 – 432
43
0
2.
CO
NTR
O
L O
F
DF
IG
Th
e
Doub
ly fed
indu
ctio
n g
e
n
e
rat
o
r’s (DFIGs)
con
t
ro
l is
typ
i
cally b
y
fi
el
d o
r
i
e
nt
at
i
o
n
of
t
h
e
gri
d
vol
t
a
ge
. T
h
i
s
cont
rol
m
e
t
hod i
s
cal
l
e
d di
r
ect
st
at
or
fl
u
x
ori
e
nt
at
i
on (D
SFO
). DF
IGs can
nei
t
h
er be
sim
p
l
y
in
teg
r
ated
with
in
m
i
cro
-
grids n
o
r b
e
connected
to
weak
g
r
i
d
s, as th
ey can
no
t con
t
ro
l th
e g
r
id
v
o
ltag
e
and
fre
que
ncy
.
Wh
en t
h
e wi
nd e
n
ergy
pe
net
r
at
i
o
n l
e
vel
i
s
hi
gh
, it
may b
e
essen
tial fo
r
wind
g
e
n
e
ration
s
to
h
a
v
e
cont
rol
gri
d
f
u
nct
i
o
n
s
re
g
u
l
a
r
l
y
associ
at
ed
wi
t
h
usual
p
o
w
er
ge
nerat
i
o
n
uni
t
s
.
Thi
s
p
r
obl
em
becom
e
s m
o
re
critical in
an
iso
l
ated
power syste
m
l
i
k
e
th
at o
f
a
rem
o
te area wh
ich
h
a
s po
or ab
ility o
f
po
wer regu
latio
n
.
A
new
wi
n
d
par
k
usi
n
g DF
I
G
s
m
a
y i
n
fut
u
r
e
be req
u
i
r
ed
t
o
gi
ve ad
va
n
ced gri
d
su
pp
ort
f
o
r t
h
e co
nt
r
o
l
of
activ
e
po
w
e
r
f
r
eq
u
e
n
c
y
an
d r
e
activ
e po
w
e
r
an
d vo
ltag
e
.
The reactive
power voltage
support can be
ac
hieve
an
d
/
o
r
b
y
con
t
ro
lling
th
e
q-ax
is curren
t
o
f
th
e
g
r
i
d
-si
d
e
con
v
e
rter. Th
e
g
r
id
frequ
e
n
c
y is m
a
in
tain
in
a
DSFO
direct stator
fl
u
x
o
r
i
e
nt
at
i
o
n cont
rol
l
e
d
D
F
I
G
t
h
r
o
ug
h a re
serve act
i
v
e
p
o
w
er a
v
ai
l
a
bl
e b
y
operat
i
ng
bel
o
w t
h
e
m
a
xim
u
m
pow
er p
o
i
n
t
,
c
o
m
m
onl
y
referre
d
t
o
as “del
oa
di
ng”
[
7
]
.
It
i
s
do
ne by
pi
t
c
he
s cont
rol
an
d/
or
t
o
r
que
cont
rol
(i
.e.
,
i
n
ert
i
a
l
ene
r
gy
st
ora
g
e)
.
Apa
r
t
fr
om
t
h
e fact
that these
m
e
thods
nee
d
a
non m
a
xim
u
m
powe
r
poi
nt
o
p
erat
i
o
n
,
t
h
e de
gree
of
fre
que
ncy
su
p
p
o
r
t
i
s
l
i
m
i
t
e
d.
It is also
p
o
ssib
l
e to
m
a
in
tai
n
th
e grid
frequ
en
cy
t
h
r
o
u
g
h
u
s
i
n
g
t
h
e ene
r
gy
st
o
r
ed i
n
a
n
e
x
t
e
r
n
al
ES,
i
n
al
l
t
h
ese m
e
t
hods,
h
o
we
ver
,
a
n
ext
e
r
n
al
v
o
l
t
a
g
e
an
d
freq
u
e
n
c
y sou
r
ce is still requ
ired as th
e DFIGs
u
s
e
fi
el
d o
r
i
e
nt
at
i
on o
f
t
h
e
vol
t
a
ge
s
o
u
r
ce.
An
ot
he
r co
nt
r
o
l
m
e
t
hod f
o
r
D
F
IG
s i
s
cal
l
e
d i
ndi
rect
st
at
o
r
fl
ux
orien
t
ation
(ISFO). Th
is co
n
t
ro
l th
e
stator
fl
ux
is no
lo
ng
er d
e
termin
ed
b
y
th
e grid
vo
ltag
e
bu
t
b
y
th
e ro
tor ex
citatio
n
curren
t
th
e stato
r
fl
ux
ang
l
e
is set thr
oug
h
f
r
e
e ru
nn
ing in
tegr
atio
n of
t
h
e
r
e
f
e
r
e
n
c
e st
ato
r
vo
ltag
e
f
r
eq
u
e
n
c
y
Fs
*.
Th
e stator
vo
ltag
e
is
cont
rol
l
e
d
t
h
r
o
ug
h
re
g
u
l
a
t
i
ng t
h
e
r
o
t
o
r
d
-
a
x
i
s
cu
rre
nt
i
rd
. DF
IG a
ppe
ars l
i
k
e
a vol
t
a
ge a
n
d
fre
que
ncy
s
o
u
r
ce i
n
th
e po
wer syste
m
b
y
th
e ISFO-con
tro
lled.
By th
e lo
ad
itself, no
w t
h
e po
wer d
e
li
v
e
red is d
e
term
in
ed
an
d
i
s
efficiently user de
fi
ned. The
r
e
is no
direct electrical torque
T
e
co
n
t
ro
l
o
f
t
h
e DFIG. Th
is is a q
u
a
lity o
f
ISFO
cont
rol beca
us
e the
q-com
p
on
ent of stator
current
i
sq
is set b
y
th
e lo
ad
. It is actu
a
lity
t
o
m
a
in
tain
th
e
fi
eld
ori
e
nt
at
i
on o
f
t
h
e DF
IG
t
h
e
q
-
com
p
onent of
ro
tor current i
rq
pr
op
ort
i
o
nal
t
o
i
sq.
Th
e m
a
i
n
ch
alleng
e in
micro
gri
d
(M
G) is
associated wit
h
islande
d
operation.
Whe
n
the m
i
cro
gri
d
s a
r
e c
o
nnect
ed to m
a
in grid, the
refe
rence
v
o
l
t
a
ge an
d
fre
qu
en
cy
are fi
xe
d
by
gri
d
. I
n
t
h
e ca
se of i
s
l
a
nde
d
ope
rat
i
o
n, es
pe
ci
al
l
y
for hi
gh
wi
n
d
ener
gy
penet
r
a
t
i
on, t
h
e l
o
cal
gri
d
vol
t
a
ge
an
d
fre
que
ncy
c
o
nt
r
o
l
i
s
q
u
i
t
e
di
ffi
cul
t
as
Fi
g
u
r
e
1.
Fig
u
r
e
1
.
A stud
y on
Micro
grid
conf
igu
r
ation
2.
a. Dr
oo
p Co
ntr
o
l
o
f
Ge
ner
a
t
o
rs
The d
r
oo
p m
e
tho
d
i
s
t
h
e m
o
st
wel
l
-
kn
o
w
n
m
e
t
hod f
o
r l
o
a
d
sha
r
i
n
g i
n
m
i
cro
g
ri
d
s
. D
r
o
op c
ont
rol
o
f
gene
rato
rs is n
ecessary
fo
r re
al and reactive
po
wers
s
h
ari
n
g dem
a
nded
b
e
t
w
een sev
e
ral
generat
o
r s
o
u
r
ces as
Fig
u
re 2
.
In
m
i
crog
ri
d
s
, th
ere h
a
s b
e
en
m
u
ch
resear
ch
ad
dressin
g
system
s
t
ab
ility an
d
p
e
rform
a
n
ce relia
b
ility
u
n
d
e
r h
a
rm
o
n
i
c an
d
un
b
a
lanced
cond
itio
n
s
. In
th
e case
of in
term
itten
t
r
e
n
e
wab
l
e so
urces. Very little
work
has been
for
the case of droop cont
ro
l in
wh
ich
each DG sou
r
ce
ou
tpu
t
is v
a
riab
le and
,
in
gen
e
ral
,
i
nde
pen
d
e
n
t
o
f
one a
not
her
.
The rat
i
n
g
of
p
o
we
r an
d e
n
er
gy
an ES
fo
r a wi
n
d
fa
rm
empl
oy
i
n
g d
r
o
o
p
cont
rol
is d
i
scu
ssed
in
wh
ich
real
wind
profile and
PSCAD
sim
u
lat
i
o
n
.
Furth
e
r an altern
ativ
e droo
p
con
t
ro
l in
wh
ich
th
e dr
oop
slope r
e
fl
ect
s t
h
e t
r
ansm
i
t
t
e
d shaft
po
we
r.
A va
ri
ous
D
f
i
g
sy
st
e
m
s operat
e
d
w
i
t
h
dr
o
op c
o
nt
r
o
l
al
so
d
i
scu
s
sed [4
-5
].
2
.
b.
V
a
ria
b
le D
r
oo
p
Co
nt
rol
Dr
oo
p
co
nt
r
o
l
i
s
de
vel
o
ped
f
o
r
va
ri
o
u
s
DF
I
G
s.
The
DFI
G
s f
r
eq
ue
ncy
a
n
d
out
p
u
t
p
o
w
er
o
f
DF
IGs
i
s
i
nve
rsel
y
pr
op
ort
i
o
nal
.
T
h
e i
n
p
u
t
p
o
we
r t
o
t
h
e dr
o
op c
ont
rol
i
s
n
o
l
o
n
g
e
r
a
m
u
t
u
al
co
m
ponent
o
f
t
h
e l
o
ad
po
we
r
but
i
s
pa
rt
i
a
l
by
t
h
e
p
r
e
s
ent
e
d
wi
nd
an
d E
S
po
wer
.
W
h
ere
as i
n
a st
a
nda
r
d
dr
oo
p c
o
nt
r
o
l
.
Evaluation Warning : The document was created with Spire.PDF for Python.
I
J
PED
S
I
S
SN
:
208
8-8
6
9
4
Dro
o
p
C
har
act
e
ri
st
i
c
s of
D
o
u
b
l
y
Fe
d I
n
duct
i
on
Ge
ner
a
t
o
r
Ener
gy
St
or
a
g
e
Syst
e
m
s w
i
t
h
i
n
…
(
K
.L. Sire
esha)
43
1
2.c
.
St
a
n
d
a
rd
D
r
oo
p
Co
nt
rol
Th
e f-P
droop
g
a
in
is set as
m=
∆
f/P
no
m
(
∆
f
i
s
t
h
e m
a
xim
u
m
freq
u
e
n
cy
d
e
vi
at
i
on
w
h
i
c
h
i
s
kept
e
q
ual
fo
r all gene
rators a
nd
P
nom
i
s
t
h
e rat
i
ng
of t
h
e ge
nerat
o
r
)
.
As a res
u
lt, th
e d
e
m
a
n
d
sh
ared
is p
r
op
ortio
n to
th
e
gene
rator rating. B
u
t it
m
a
y not be t
h
e fi
nest shari
n
g
m
e
thod for an i
n
term
ittent generati
on like
wind energy
.
To
exp
l
ain
th
is, co
nsid
er a situ
atio
n, in
wh
ich
th
e ex
t
r
act
ab
l
e
wi
nd
po
wer
i
n
one
of t
h
e
DFI
G
(e
.g
., D
F
IG
2
)
d
r
op
s
b
e
low t
h
e co
n
t
ri
bu
tion
requ
ired
. B
y
th
e actio
n
o
f
its
d
r
oo
p co
n
t
ro
ller, th
is
redu
ction
cau
s
es th
e
ope
rat
i
o
nal
fre
que
ncy
t
o
i
n
c
r
ease fr
om
f
op
to
f
1
o
p
. Du
e to
th
is, th
e o
t
h
e
r
DFIG
p
o
wers is redu
ced
to
co
m
p
ly
with
th
e n
e
w op
eration
a
l
frequ
e
n
c
y (i.e., f
1
o
p
). Th
is
o
p
e
ratio
n
a
l d
e
ficien
cy is feasib
le
o
n
l
y if th
e syst
e
m
h
a
s
an alternative
powe
r source
(the
AG i
n
thi
s
case) to
t
a
ke
ove
r t
h
e
p
o
w
e
r i
rres
p
ect
i
v
e
of t
h
e wi
nd
po
we
r
av
ailab
l
e to th
e o
t
h
e
r
DFIGs [5
].
On
e
of th
e m
a
in
so
l
u
tio
ns for th
is
d
i
fficu
lty is to
m
a
k
e
t
h
e dro
o
p
co
efficien
ts reflect th
e availab
l
e
w
i
nd
pow
er.
O
u
t
p
u
t
po
w
e
r o
f
Df
ig
s can stay sa
m
e
o
r
it
m
a
y in
crease (it is subj
ect to
th
e
wind p
o
wer
accessibility) following the
wind power reduction in the DFIG2.
This can be
achieved if the droop
coefficients change as a c
u
bic function of
ω
r,
i.e.,m
=
∆
f/k
opt
ω
r
3
, whe
r
e k
op
t
i
s
a gi
ve
n co
nst
a
nt
f
o
r m
a
xim
u
m
po
we
r t
r
acki
n
g o
f
wi
n
d
p
o
w
er
. The m
a
i
n
adva
nt
age
o
f
t
h
e va
ri
abl
e
d
r
oo
p
gai
n
i
s
t
h
at
t
h
e po
we
r r
e
qui
red
from
the AG s
i
gnifica
ntly decreases since t
h
e DFIGs wi
t
h
th
e v
a
r
i
ab
le dr
oop
ch
ar
acteri
s
tics can com
p
ensate
fo
r the
di
ffe
ren
tial powe
r
.
Fi
gu
re
2.
F-
P
d
r
o
o
p
i
n
g c
h
arac
t
e
ri
st
i
c
s of
DF
I
G
s
3.
R
E
SU
LTS AN
D CONC
LUSIONS
Thi
s
pa
per m
a
i
n
l
y
conce
n
t
r
at
es on i
s
l
a
nde
d
m
i
crogri
d
ap
pl
i
cat
i
on. T
h
e sh
ari
n
g o
f
p
o
w
e
r
i
n
a wi
n
d
farm
i
s
al
one opt
i
m
al
by
pro
v
i
d
i
n
g t
h
e
Dfi
g
s t
h
ro
u
gh t
h
e
dr
oo
p c
h
aract
eri
s
t
i
c
s. To a
d
j
u
st
t
h
e D
F
I
G
s
out
put
po
we
r acc
or
di
ng
t
o
t
h
e
wi
nd
p
o
we
r,
a
vari
abl
e
dr
oo
p
an
d
st
an
dar
d
d
r
o
o
p
c
h
aract
e
r
i
s
t
i
c
are
nee
d
e
d
m
e
t
hods
as Figure 3. T
h
ere
f
ore, the
DFIGs ca
n com
p
ensate for each othe
r which res
u
lts in signi
fi
ca
nt
re
duc
t
i
on i
n
po
we
r dem
a
nd
ed f
r
om
AG
.
Thi
s
pape
r c
o
m
p
ares t
h
e pe
rf
orm
a
nce wi
t
h
t
h
e
va
ri
abl
e
an
d st
an
dar
d
dr
o
o
p
ch
aracteristics o
f
Dfig
s. Th
e syste
m
stab
ilit
y may b
e
a
ffected
b
y
th
e u
s
e
of th
e
v
a
riab
le dro
o
p
m
e
th
o
d
.
Figu
re (a)
Figu
re (b
)
0
0.
0
2
0.
04
0.
0
6
0.
08
0.
1
0.
12
0.
14
0.
1
6
0.
18
0
1
2
3
4
5
6
7
T
i
m
e
|
(
se
c)
D
F
IG
ra
ti
n
g
s
(p
.u
)
0
0.
2
0.
4
0.
6
0.
8
0
0.
2
0.
4
0.
6
0.
8
0.
8
0.
6
0.
4
0.
2
0
0.
2
0.
4
0.
6
0.
8
0
Ti
m
e
D
fi
g
R
at
i
n
g (
p
u)
Evaluation Warning : The document was created with Spire.PDF for Python.
I
S
SN
:
2
088
-86
94
I
J
PED
S
Vo
l.
6, No
. 3, Sep
t
em
b
e
r
2
015
:
42
9 – 432
43
2
Figu
re (c)
Figure
(d)
Fi
gu
re
3.
The
c
o
m
p
ari
s
on
s
of
dr
o
o
p
cha
r
act
e
r
i
s
t
i
c
s per
f
o
rm
ances
DF
IGs
r
e
duce
t
h
e
spee
d
of
wi
nd
.
REFERE
NC
ES
[1]
Meghdad Fazel
i, Greg M. Asher
,
Christian Klum
pner, Li
angzhon
g Yao, a
nd Masoud Bazargan
,
“
N
ovel Integra
tio
n
of W
i
ndGenerat
orEnerg
y
S
t
orag
e S
y
s
t
em
s
withi
n
M
i
crogrids
”
,
I
EEE transact
i
on
s on smart grid
, vol. 3, no
. 2, June
2012.
[2]
R.
H.
L
a
sse
te
r and P.
Pia
g
i,
“
Extended microgrid
using di
s
t
r
i
buted ener
gy r
e
s
ources
”, pr
es
ented a
t
the P
o
wer Eng.
Soc. Gen
.
Meet., 2007.
[3]
Z. Jiang and
R. A. Dougal, “
Hierarchica
l
micr
ogrid paradigm for inte
gration
o
f distributed energy resources
”,
presented
at th
e
Power Ener
g
y
S
o
c. G
e
n. Meet.,
2008.
[4]
C. Wang and
M. H. Nehrir
, “Analy
tical
appr
oaches
for op
ti
m
a
l plac
em
ent
of
distributed g
e
neration sources in
power s
y
s
t
em
s
”
,
IEEE Trans. Po
wer Syst.
, vo
l. 1
9
, pp
. 2068–207
6, Nov. 2004
[5]
R.
Majumder,
G.
Ledwich,
A.
Ghos
h, S. Chak
rabarti, and F. Zare
,
“Droop control of converter-interfaced micr
o
sources
in rural distributed
gen
e
r
a
tion
”
,
IEEE Trans. Power
Del.
,
vol. 25
, pp
. 2768
–2778,Oct. 2010
.
[6]
R. Majumder, B
.
Chaudhuri, A.
Ghosh,
R. Majumder, and G. Ledwich,“Improve
ment of stability and load sharin
g
in an
autonomou
s micro grid using
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droop
con
t
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IEEE Trans.
Powe
r Sy
st.
,
vol. 25
, pp
. 796
–
808, May
2010.
[7]
M.
Sha
h
a
b
i,
M. R.
Ha
ghifa
m,
M.
Mohamadian, and S. A. Nabavi-Niak
i
, “Microgrid d
y
n
a
mic performance
improvement using a doubly
fe
d Induction wind generator”,
IEEE Trans. Energy Converters.
vol. 24, pp. 137–145,
Mar. 2009
.
BIOGRAP
HI
ES OF
AUTH
ORS
K.L.
S
i
re
es
h
a
Received B
.
Tech in Elec
trical
and Electronics Engi
neer
ing in P.V.P Siddhartha
engineering col
l
ege, Vijay
a
w
a
da, in 2009 and
M.Tech in
Sasi institute of technolog
y,
Tadep
lligud
em, in 2012.Now currently
workin
g to
wards PH.
D
degree in the Department of
power s
y
s
t
em
s
in K L UNIVERS
ITY, Guntu
r
Res
ear
ch in
te
res
t
ed
areas
are
facts
,
power
s
y
s
t
em
s
,
Ren
e
wable
en
erg
y
s
our
ces
.
G. Kesava Rao
awarded
Ph.D.
in Electrical Po
wer S
y
st
ems at
Moscow Powe
r Engg. Institute,
Moscow, U. S.
S. R. in 1973,
M.Sc (Engg.) in
Electrical Machine Design at
Guind
y
Engg
.
College, Chenn
a
i, 1963 and
B.E. (Elec.) at Govt
. College of En
gineer
ing, Kak
i
nada (Andhra
Universit
y
), 196
0. He has 41
y
ears of tea
c
hing
experien
ce
at
various institu
te
s like BHUIT,
Varanasi, VVIT,
Nambur
,
LBR
C
college of
Engineer
ing,
M
y
lavaram, Vignan
s
engineering
College
&
Vign
ans Universit
y
,
Vadlamudi. He
published 32
Inte
rnational Journals, 12Nation
a
l
Journals, 8
Inter
n
ation
a
l Conf
ere
n
ces
and
21 N
a
ti
onal Conf
eren
ce
s
.
0
0.
2
0.
4
0.
6
0.
8
0
0.
8
0.
6
0.
4
0.
2
0
0.
2
0.
4
0.
6
0.
8
0
0.
2
0.
4
0.
6
0.
8
t
i
m
e
(
pu)
d
fi
g
ra
ti
n
g
(p
u
)
0
0.
2
0.
4
0.
6
0.
8
0
0.
2
0.
4
0.
6
0.
8
0
0.
2
0.
4
0.
6
0.
8
0
0.
2
0.
8
0.
6
0.
8
ti
m
e
(
s
e
c
)
D
f
i
g
ra
t
i
n
g
(p
u
)
Evaluation Warning : The document was created with Spire.PDF for Python.