TELKOM
NIKA Indonesia
n
Journal of
Electrical En
gineering
Vol.12, No.4, April 201
4, pp. 3230 ~ 3
2
3
9
DOI: http://dx.doi.org/10.11591/telkomni
ka.v12i4.4941
3230
Re
cei
v
ed Se
ptem
ber 25, 2013; Revi
se
d No
vem
ber
22, 2013; Accepted Decem
ber 11, 20
13
Coordination of Distributed Generators and Energy
Storage Systems
Yu Wenpe
ng
*
1
, Liu Dong
2
, Huang Yuh
u
i
3
Ke
y
Lab
orator
y of Control of Po
w
e
r T
r
ansmission
a
nd C
onv
ersio
n
, Ministr
y
of Educatio
n,
Schoo
l of Elect
r
onic, Informati
on an
d Electric
al Eng
i
ne
eri
ng,
Shang
ha
i Jiao
T
ong Univ
ersit
y
,
#80
0, Don
g
chu
an Ro
ad, Sha
n
gha
i, Chin
a. 20
024
0
*
C
o
rre
sp
on
d
i
ng
a
u
t
h
o
r
, e
-mail
:
y
u
.
w
en
pe
ng@
sj
tu
.e
du
.cn
1
, don
gli
u
@sjtu.
e
du.cn
2
, h
y
h8
30
7@sjtu.e
du.cn
3
A
b
st
r
a
ct
As the int
e
rco
nnecti
on
of di
stributed
ge
ne
rati
on (
D
G) an
d en
ergy stor
age syste
m
(
ESS), th
e
oper
ation
of D
G/ESS shoul
d
be
opti
m
i
z
e
d
a
nd c
oord
i
nat
ed
. The inter
m
ittence
of ren
e
w
able
en
ergy
an
d
th
e
error
of the
lo
a
d
forec
a
stin
g,
w
h
ich is
usu
a
l
l
y
take
n
as
the
raw
data
of th
e g
l
ob
al
opti
m
i
z
a
t
i
o
n
al
gor
ith
m
,
cause
differe
nc
e betw
e
e
n
the
actual
an
d the
opti
m
a
l
op
erati
ng status
of th
e netw
o
rk. F
e
e
der C
ontrol
Err
o
r
(F
CE) is propo
sed b
a
sed
on
the diffe
re
nce
betw
een the
a
c
tual an
d the
opt
i
m
a
l
net lo
a
d
of the netw
o
rk,
and
q
uantifi
e
s
the
op
eratin
g
error
of
th
e n
e
tw
ork. A coor
din
a
ting
co
ntro
l syste
m
of al
l
the
DG/ESS i
s
proposed based on FCE, an
d 3
differ
ent
control m
o
des are put
forw
ards.
With the coordination system
,
the
differenc
e betw
een th
e actua
l
and th
e opti
m
a
l
net lo
ad ar
e b
a
la
nced
by all t
he DG/ESS pr
oporti
ona
lly, an
d
this reduc
es the oper
atin
g err
o
r relati
v
e
to the opti
m
a
l
op
eration status.
Ke
y
w
ords
:
fe
eder c
ontrol
e
rror, coordi
nati
on co
ntrol,
dis
t
ributed
gen
er
ation,
e
nergy
storage syste
m
,
oper
ation opti
m
i
z
at
io
n
Copy
right
©
2
014 In
stitu
t
e o
f
Ad
van
ced
En
g
i
n
eerin
g and
Scien
ce. All
rig
h
t
s reser
ve
d
.
1. Introduc
tion
With the tech
nology devel
opment of smart
grid, mo
re and mo
re
Distri
buted G
enerator
(DG)
and
En
ergy Sto
r
age
System (ESS
) a
r
e
co
nne
ct
ed to th
e di
st
ribution
line.
The
ope
ratin
g
of
DGs and ES
S should be optimized and coordinate
d to promote the benefit of DG/ESS [1-2] and
put off the up
grad
e of the
netwo
rk [3]. Many
stu
d
ie
s have be
en
carri
ed o
u
t on
the optimi
z
ati
on
and the real-t
ime cont
rol of
DG/ESS. Wang [4] and
Il-Yop
[5] propo
sed a d
r
oo
p control ba
se
d on
P-f and
Q-V
chara
c
te
risti
c
s, [6-9] propo
sed the
co
ordi
nated
real
-tim
e control
of E
SS to sup
p
re
ss
the intermittenc
e of the renewabl
e energy. The
operating of
DG/ESS
is
optimiz
e
d in [10-11] to
redu
ce the p
eak-valley differen
c
e of th
e load. Op
ti
mization of wind-di
esel sy
stem with ES
S is
proposed i
n
[12], and the
active
management of
DG/
ESS are analyzed i
n
[13-15]
consideri
n
g
the line-lo
ss, co
st of electri
c
ity and rea
c
t
i
ve compe
n
sation.
The forecast
ed data
of th
e po
we
r of lo
ad an
d rene
wabl
e en
ergy
is u
s
u
a
lly taken a
s
the
raw data
of the
global optimization system
of
DG/ESS and the network. However, there is
differen
c
e b
e
twee
n the fore
ca
sted value
and the a
c
tu
a
l
value. More
over, the glob
al optimizatio
n
is time-co
n
su
ming an
d is
e
x
ecuted i
n
lo
ng-te
rm cy
cle
.
The po
we
r
of the load a
n
d
the re
ne
wa
ble
energy are
chang
ed du
rin
g
the optim
ization cycl
e. T
h
is cau
s
e
s
th
e different be
tween the
act
ual
operating stat
us an
d the op
timal
operatin
g status of th
e netwo
rk.
Feede
r
Control Erro
r (FCE
) is p
r
o
posed
based on th
e different b
e
t
ween th
e a
c
tual net
load
and
the
optimal n
e
t lo
ad of th
e di
st
ribution
line, and FCE qua
ntifies
the
op
erating
e
rro
r of
the whole net
work
. Then a
c
o
ordinating
c
ontrol
s
y
s
t
em of all the
DG/ESS is
proposed
bas
e
d
on
FCE, and 3
different co
ntrol mod
e
s a
r
e put forwa
r
d
.
With the co
ordin
a
tion of the system, the
differen
c
e b
e
twee
n the act
ual net load
a
nd the opt
ima
l
net load is b
a
lan
c
ed p
r
op
ortionally by
all
of the DG/ESS. Finally,
the coordi
nati
ng cont
rol sy
stem based
on FCE is demonstrated and
verified in the c
a
se s
t
udy.
2. Definition
of Feed
er Co
ntrol Error a
nd Consis
te
nt Ne
t Load
Con
t
rol Mod
e
In the traditional distri
bution network, DG
s/ESS are
operated indepen
dently, lacking of
coo
r
din
a
tion
with ea
ch
other, an
d the
power inte
rm
ittence of ren
e
wa
ble en
ergy gene
ratio
n
is
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Coo
r
din
a
tion
of Distrib
u
ted
Generators a
nd Energy Storag
e Sy
ste
m
s (Yu Wen
p
eng)
3231
depressed wi
th local ESS.
With the technology dev
elopment of
smart grid, the amount of grid-
con
n
e
c
ted DGs an
d the p
enetratio
n
of rene
wa
bl
e en
ergy incre
a
se, and the op
eration
of DG
s
and ESS in the network
should be
coordinated.
In order to
coordi
nate the operations
of
DGs and
ESS, the operating status of the
netwo
rk n
eed
s to be estim
a
ted and qu
a
n
tified. T
here
is usually a
global op
eration optimization
system
for th
e net
work,
a
nd the
optim
al net l
oad
of
the n
e
two
r
k
is
cal
c
ulate
d
, co
nsi
deri
ng
the
load a
nd
wea
t
her forecasti
ng. Ho
weve
r,
error
ex
iste
s in the lo
ad a
nd weathe
r f
o
re
ca
sting, a
nd
this ca
uses d
i
fference bet
wee
n
the act
ual ope
rati
ng
status an
d o
p
timal ope
rati
ng statu
s
of the
netwo
rk. If th
e actu
al n
e
t load of th
e ne
twork i
s
g
r
eat
er tha
n
the
o
p
timal on
e, it denote
s
h
eav
ier
load o
r
le
ss
power
of DG
than exp
e
ct
ed. On th
e
o
ppo
site, the li
ghter
actu
al
net load
de
n
o
tes
lighter loa
d
of greate
r
po
we
r of DG than
expecte
d.
To q
uantify the a
c
tual
op
erating
statu
s
of
the
netwo
rk, F
eed
er Control E
r
ror (FCE) is
defined a
s
th
e differen
c
e
betwe
en a
c
tu
al net load
a
nd the optim
al net load of
the distrib
u
tion
line, as sho
w
n in (1):
__
NL
A
N
L
O
FCE
P
P
(
1
)
Whe
r
e
_
NL
A
P
is the actual value
of the net load of
the distri
bution line, which i
s
got fro
m
the mea
s
u
r
e
m
ent sy
stem, and
_
NL
O
P
is the
o
p
timal value
cal
c
ulate
d
by
the glob
al o
p
timization
system. The
plus di
re
ction
of
_
NL
A
P
and
_
NL
O
P
is to
inject in the di
stribution line.
Ac
c
o
rdingly, the
governing
equation of DG/ESS in c
o
ns
is
tent
net load
c
ontrol mode
based on F
C
E is sho
w
n i
n
(2), whe
r
e
i
is the power coo
r
dinatio
n
coefficie
n
t of
th
i
DG/ESS,
and
i
P
is the p
o
we
r re
gulati
ng amo
unt.
_
iO
P
is the optim
al
powe
r
of
th
i
DG/ESS at tim
e
T
cal
c
ulate
d
by the global o
p
timization
syst
em, and
i
P
is the regul
ating target.
__
0
_
()
()
()
()
T
ii
N
L
A
N
L
O
ii
O
i
P
T
PPd
t
PT
P
T
P
T
(
2
)
The net load
error of the d
i
stributio
n lin
e is sup
p
o
s
e
d
to be
_
NL
E
r
r
P
at
0
T
, and
after
the coordination process the power regul
ating
amount of DGs/ESS are calculated by (3):
_
0
N
iN
L
E
r
r
i
j
j
PP
(
3
)
W
h
er
e
N
is
t
he
c
o
unt of
power adjus
t
able
DGs
/
ESS. The net load error of the
distribution
line will
be bal
anced by
all
of
t
he
power
adjustable DGs/ESS proportionally
to t
he
power coo
r
di
nation coeffici
ent, and the a
c
tual net lo
a
d
is kept con
s
i
s
tent with the
optimal value.
Figure 1.
Coo
r
din
a
tion
System Base
d on FC
E in
Con
s
i
s
tent Net Load Control Mode
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 23
02-4
046
TELKOM
NI
KA
Vol. 12, No. 4, April 2014: 3230 – 3
239
3232
The coordina
tion system
b
a
se
d on F
C
E
in con
s
i
s
tent
net load
cont
rol mod
e
is
shown in
Figure 1. T
h
e ideal
optimal
power
of all t
he po
wer adj
u
stabl
e DG/ESS in the di
st
ribution line
are
cal
c
ulate
d
by the global o
p
timization
system co
nsi
d
ering the l
o
a
d
fore
ca
sting
and re
ne
wa
ble
energy fore
casting. As th
e erro
r
of the fore
ca
sting
,
there is
un
expecte
d po
wer
of load
s or
rene
wa
ble en
ergy gene
rati
on.
Th
e
e
r
ror of
the net
lo
a
d
(F
CE) i
s
cal
c
ulate
d
a
nd
multiplied
by t
h
e
coo
r
din
a
tion
coeffici
ent, th
en the
po
we
r reg
u
lation
a
m
ount of
DG
is
cal
c
ulate
d
with th
e inte
gral
of FCE (1/s in
Figure 1
)
. After the co
ordin
a
tion,
the une
xpected n
e
t load is b
a
lan
c
ed by all of the
power adj
ust
able DGs/ES
S, and the actual net load
i
s
ke
pt con
s
i
s
tent with its op
timal value.
Con
s
id
erin
g t
hat the gl
obal
optimization
algorit
h
m
is time-con
sumi
n
g
, the ap
plica
t
ion of
the co
ordina
tion syste
m
based
on
FCE
c
an
regul
ate the
power
adj
ustabl
e DGs/ESS
autonom
ou
sl
y betwee
n
th
e optimizatio
n cycl
e. The
coo
r
din
a
tion
system
also
sup
p
re
sse
s
the
impact of the
forecastin
g error o
n
the
op
erating
status of the whole
line.
3. Biased
Ne
t Load Contr
o
l Mode Bas
e
d on Feed
e
r
Control Error
All the unexpected
power
of the net l
o
ad is
balanced by the
DGs/ESS in the network i
n
the con
s
iste
nt net loa
d
control mo
de
. Ho
weve
r, t
he un
expe
cted net l
oad
may exce
ed
the
regul
ating
capacity of the
DGs/ESS,
th
erefore the biased net lo
ad cont
rol mode is proposed.
The mod
e
l of FCE in this m
ode is
sho
w
n
in (4):
__
_
_
11
iN
L
A
N
L
O
i
A
i
O
i
FC
E
P
P
P
P
K
(
4
)
W
h
er
e
_
iA
P
and
_
iO
P
are
the
actu
a
l
po
wer a
nd
optimal p
o
we
r of
th
i
DG/ESS,
K
is
the
deviation coe
fficient of the net load.
i
F
CE
is the FCE for
th
i
DG/ESS, and the other variables
have the same meani
ng
with that
in (1-2). The governing equa
tion of DGs/
ESS is (5), where
()
i
PT
is the regul
ating target of
th
i
DG/ESS.
__
_
_
0
_
11
()
()
()
()
T
iN
L
A
N
L
O
i
A
i
O
i
ii
O
i
PT
P
P
P
P
d
t
K
PT
P
T
PT
(
5
)
After the coordination, the
deviation of t
he net lo
ad
(
NL
P
) relative to its optimal value i
s
cal
c
ulate
d
by (6), an
d the
p
o
we
r re
gulati
ng amou
nt of
th
i
DG/ESS is
c
a
lc
ulated by (7).
_
1
=(
)
N
NL
N
L
E
r
r
j
j
PP
K
K
(
6
)
_
1
()
N
iN
L
E
r
r
i
j
j
PP
K
(
7
)
Acco
rdi
ng to
(6)
and
(7), th
e unexpe
cted
net load
_
NL
E
r
r
P
is
ba
la
nc
e
d
b
y
bo
th
D
G
s
/
ESS
and
external
grid
(hi
gh-volt
age
distri
buti
on n
e
two
r
k o
r
tra
n
smissio
n
g
r
id) p
r
opo
rtionally, and
the
actual net loa
d
has a devia
tion fr
om its optimal value. The co
or
di
nat
ion system b
a
se
d on FCE in
the biased ne
t load control mode is
simil
a
r to t
hat in the con
s
i
s
tent net load control mode.
4. Control Mode Considering the SOC Error of ESS
The e
nergy stora
ge
syste
m
is diffe
rent
fr
om the
po
wer adju
s
tabl
e DG.
Not o
n
ly the
charging/ discharging power, but
also the Status Of Charge
(SOC)
of ESS should be consi
dered
by the coordi
nation sy
stem. The operation of ESS i
n
a specific period of time
(e.g., 24 hours) is
optimize
d
by
the glo
bal
opt
imization
sy
stem. Corr
e
s
po
ndingly, the
SOC i
n
the
p
e
riod
of time
is
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Coo
r
din
a
tion
of Distrib
u
ted
Generators a
nd Energy Storag
e Sy
ste
m
s (Yu Wen
p
eng)
3233
also
optimi
z
e
d
. Ho
weve
r, the SO
C of E
SS in the
a
c
t
ual op
eration
is diffe
rent from the
optim
al
SOC. The
r
ef
ore, the coo
r
dinatio
n system bas
ed o
n
FCE sh
oul
d take the
SOC erro
r into
accou
n
t, and redu
ce the S
O
C e
rro
r.
The mod
e
l of FCE co
nsid
ering th
e SOC erro
r is sh
own in
(8),
where
_
iA
So
c
,
_
iO
So
c
are
the actual SO
C and o
p
tima
l SOC of
th
i
ESS, and
i
is the SOC re
gulati
ng co
efficient
.
__
_
_
_
E
r
r
_
_
11
iN
L
A
N
L
O
i
A
i
O
i
i
A
i
O
i
i
FC
E
P
P
P
P
P
Soc
Soc
K
(
8
)
The governing equation of ESS in the coordina
ting considering the
SOC error is
(9).
__
_
_
_
E
r
r
_
_
0
_
11
t
iN
L
A
N
L
O
i
A
i
O
i
i
A
i
O
i
i
ii
P
i
P
P
P
P
P
P
S
o
c
S
oc
dt
K
PP
P
(
9
)
Supposing that the act
ual powers of the loads and all
of DGs/ESS are the same as the
forecastin
g p
o
we
r o
r
th
e
optimal p
o
we
r, and
the S
O
C
error of
th
i
ESS is
_
iE
r
r
So
c
, the
power
regul
ating am
ount of DG/ESS is cal
c
ul
ated by (10)
T
he governing
equation of E
SS consideri
n
g
the SOC er
ro
r is (9
), whe
r
e
NL
P
,
i
P
and
j
P
are the power reg
u
lating amo
u
n
t of the exte
rnal
grid,
th
i
ESS and other DG/ESS respectively.
_E
r
r
0
,
i
iN
L
i
i
i
ij
N
L
ji
jN
L
j
PP
S
o
c
K
PP
P
PP
K
j
i
(
1
0
)
Then (11) i
s
derived from (10
)
, whe
r
e
1
N
j
j
A
.
_E
r
r
i
ii
i
i
AK
PS
o
c
A
K
(
1
1
)
If we
wa
nt to
redu
ce
the
S
O
C
erro
r of
th
i
ESS to 0
within the time
T
, the valu
e of
i
will
be cal
c
ul
ated
as (12), in
which
i
E
is t
he e
nergy ca
pacity of
th
i
ESS, and the ot
her
symbols
have the sam
e
meanin
g
as that in (4), (1
1).
=
i
i
ii
E
AK
TA
K
(
1
2
)
Acco
rdi
ng to
(12
)
, the val
u
e of
is
dire
ctl
y
pro
portio
n
a
l
to the
en
ergy ca
pa
city o
f
the
ESS, and is inversely proportional to the time
T
.
In this co
ntrol
mode, the u
nexpe
cted ne
t l
oad is bal
a
n
ce
d by both
external g
r
id
and all
the DGs/ESS. And besides,
there i
s
an
additional component in
the power regul
at
ing amount
to
reduc
e
the
SOC
error of ESS. If
_E
r
r
0
i
So
c
, the additional
compon
ent
will increase ESS’
discharging power or
reduce the
chargi
ng power. On
t
he opposite, t
he di
sc
harging power
will be
redu
ce
d or t
he ch
argi
ng
power be in
cre
a
sed whe
n
_E
r
r
0
i
So
c
. The SOC error tends
to
decrea
s
e
wit
h
the ad
ditio
nal re
gulatin
g
comp
one
nt, and the
sp
ee
d of the de
creasi
ng d
epen
ds
on the value
of
and the energy ca
pacity of ESS.
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 23
02-4
046
TELKOM
NI
KA
Vol. 12, No. 4, April 2014: 3230 – 3
239
3234
5. Case Stud
y
A distrib
u
tion
line
with 8 l
o
ads and
1
wi
nd ge
ne
rator
is ta
ken
as a
ca
se, in
which th
ere
are 2
grid-connected ESS and 2 po
wer adjustabl
e
DGs. The topol
ogi
cal
connection of the
netwo
rk i
s
sh
own in Figu
re
2. The electrical sp
ecifi
c
at
ion of DGs/E
SS is shown in Table 1. The
powers of loads and
wind
gene
rato
r are
shown in
0 and 0. The po
wers of load3
, load6 and
WG
cha
nge
with time.
Figure 2.
Topolo
g
ical Conne
ction
of the Net
w
ork in
Case Study
Table 1.
Electri
c
al Spe
c
ificatio
ns of
Powe
r Adjust
able DGs/ES
S
Name
Rated Po
w
e
r
Energ
y
Capacit
y
Planned Po
w
e
r
α
ESS1 80kW
160
kW*h
0kW
0.4
ESS2 80kW
400
kW*h
40kW
0.2
DG1
100kW
--
50kW
0.25
DG2
100kW
--
70kW
0.15
Table 2.
The Power of
the Load
s
Name:
Load1
Load2
Load4
Load5
Load7
Load8
Power(kW):
61.5
82
53.5
130.5
93.5
101
Table 3.
The Power of
the Load
s an
d Wind G
ene
rator at Diffe
rent Time
Time: 0-1m
1-2m
2-3m
3-4m
WG
120 kW
60 kW
120 kW
90 kW
Load3
60 kW
100 kW
60 kW
80 kW
Load6
90 kW
110 kW
90 kW
90 kW
The a
c
tual
p
o
we
rs of L
o
a
d1, 2, 4,
5,
7,
8 a
r
e
equ
al to thei
r foreca
sted
po
wer. Th
e
forecaste
d
p
o
we
rs
of WG, Load
3 an
d Loa
d6 a
r
e
120
kW, 6
0
kW an
d 90
kW. As the p
o
we
r
cha
ngin
g
of WG, Loa
d3
and Lo
ad6, there i
s
di
fference betwee
n
fore
ca
sted
value and a
c
tual
value, a
s
sho
w
n i
n
Fi
gure
3. The
po
we
r re
gulation
ra
nge
s of ESS
1,2 an
d
DG1,
2 relative to t
he
their optimal
power a
r
e
80
k
W
,
40
k
W
,
50
k
W
and
30
k
W
.
Figure 3.
The Actual V
a
lue an
d Plan
Value of Exchang
ed Powe
r of ADN line
The
coo
r
din
a
t
ion syste
m
is built
with the
Matlab Si
mulation, an
d the op
erati
ons i
n
different co
ntrol mode
s are simulate
d.
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Coo
r
din
a
tion
of Distrib
u
ted
Generators a
nd Energy Storag
e Sy
ste
m
s (Yu Wen
p
eng)
3235
5.1. Demons
tratio
n of th
e
Consis
ten
t
Net L
o
ad Co
ntrol Mode
The co
ordina
tion control system of ESS1 is
sho
w
n
in Figure 4,
whe
r
e “PE_E
r
r” is the
error of the net load, and “0.4” is the po
wer
coo
r
di
n
a
tion coeffici
en
t of ESS1. “PI” is prop
ortio
n
integral, “ES
S
1_P_Plan” is the optimal
value
of the power of ESS1, and “ESS1_Ctrl
”
is the
control si
gnal
of ESS1 after the
coordination. T
he coordinate
control
system
s of E
SS2, DG1 and
DG2 are
s
i
milar with that of
ESS1.
Figure 4.
Coordinate Control System
of
ESS1 in Consi
s
t Ex
changed Power Mode
The a
c
tual
ne
t load of th
e
distrib
u
tion li
n
e
wi
th th
e
co
ordin
a
tion
sy
stem in
con
s
i
s
tent n
e
t
load
cont
rol
mode i
s
sho
w
n in
Figu
re
5. The p
o
wer of load
s a
n
d
wind
gen
erator
cha
nge
s at
the
time 1, 2,
3,
and
the
op
eration
s
of E
SS1, 2
a
nd DG1, 2 are
regulate
d
by
t
he coo
r
din
a
tion
system to
ke
ep the
actu
al
net loa
d
co
nsi
s
tent
with
the optimal
value. The
a
c
tual p
o
wers o
f
DG/ESS are
s
h
own in Figure 6,
whic
h
s
h
ows
that
the powers
of DG/ESS
will inc
r
eas
e
when
there a
r
e po
si
tive unexpect
ed net load
to
balan
ce the
unexpe
cted n
e
t load.
Figure 5.
The Actual V
a
lue an
d Opti
mal Value of
the Net Lo
ad i
n
Con
s
i
s
tent Net Loa
d Co
ntrol
Mode
Figure 6.
The Power of
DG/ESS in Cons
i
s
tent Exchanged Power Cont
rol Mode
Table 4.
Unexpected Power of Load and
WG, and the Power Regul
ation of DG/ESS
Time:
0
-1 min
1-2 min
2-3 min
3-4 min
Unexp
e
cted po
wer of Loads an
d
WG:
0
120kW
0
50kW
The po
wer r
egulation
w
i
th the
coordina
tion sy
stem
in consistent net load control mod
e
ESS1 :
0
48kW
0
20kW
ESS2 :
0
24kW
0
10kW
DG1 :
0
30kW
0
12.5kW
DG2 :
0
18kW
0
7.75kW
Error o
f
the net l
oad after t
he coo
r
dination:
0
0
0
0
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 23
02-4
046
TELKOM
NI
KA
Vol. 12, No. 4, April 2014: 3230 – 3
239
3236
The power regulation of DG/ESS is
s
h
ow
n in Table 4. During the time period
1,
2
m
i
n
the unexp
e
ct
ed po
we
r i
s
120
kW, a
nd t
he po
we
r reg
u
lation
s of E
SS1,2 and
DG1,2 a
r
e 4
8
k
W,
24kW, 30
kW and 1
8
kW re
spe
c
tively, which hav
e the same
pro
portio
n
with thei
r p
o
we
r
coordination
coeffici
ent. The unexpected power is
balanced by DG/ESS,
and the actual net l
oad
with the co
ordination i
s
eq
ual to the optimal value.
5.2. Demons
tratio
n of th
e
Biased
Net
Load Co
ntro
l Mode
The coordinate control sy
stem of ESS1 in
biased net load control mode is
shown in
Figure 7, in which “1.0” is the deviation
coeffici
ent of the net load, and “
ESS1_P
_A” is the act
ual
value of ESS
1. The
othe
r
symbol
s h
a
ve
the
sam
e
me
aning
with
th
at in Fig
u
re 4
.
The
co
ordi
n
a
te
c
ontrol s
y
s
t
ems
of other E
SS/DG are
s
i
milar with that of ESS1.
Figure 7.
Coordinate Control System
of
ESS1 in Biased Exchanged Power M
ode
The a
c
tual n
e
t load of the distrib
u
tion
line
with the
coordinatio
n
system in bi
ase
d
net
load control
mode is
sho
w
n in Figu
re
8. There
is
still deviation
the actual n
e
t load with
the
coo
r
din
a
tion i
n
the biase
d
net load co
ntrol mode
fro
m
the optimal net l
oad, and the deviation is
smalle
r th
an
that with
out
the
coo
r
din
a
tion
sy
stem
. The
deviation of th
e n
e
t
load
after t
he
coo
r
din
a
tion
depe
nd
s on the deviation
coeffici
ent of the net load (
K
). The po
we
r regul
ation of
DG/ESS and the deviation of the net load are show
n in Table
5, which shows that half
of th
e
unexpected
power i
s
bal
an
ced
by DG/ESS and the
rest is bal
an
ced by the
external
gri
d
. The
power regulation of DG/ESS and deviation of t
he net load hav
e the same
proportion wi
th
DG/ESS’ coordination coef
ficient
and the deviation
coefficient of
t
he net load,
and thi
s
verifi
e
s
the Equation
(6), (7).
Figure 8.
The Net Lo
ad
of the Line in Biased Net Load Control
Mode
Table 5.
The Power Regulation of DG/
ESS in Biased Net L
oad Control Mode
Time:
0
-1 min
1-2 min
2-3 min
3-4 min
Unexp
e
cted po
wer of Loads an
d
WG:
0
120kW
0
50kW
The po
wer r
egulation
w
i
th the
coordina
tion sy
stem
in biased net load control mode
ESS1 :
0
24kW
0
10kW
ESS2 :
0
12kW
0
5kW
DG1 :
0
15kW
0
6.25kW
DG2 :
0
9kW
0
3.75kW
Deviation of the
net load after
t
h
e
coordination:
0
60kW
0
25kW
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Coo
r
din
a
tion
of Distrib
u
ted
Generators a
nd Energy Storag
e Sy
ste
m
s (Yu Wen
p
eng)
3237
5.3. Demons
tratio
n of th
e
Contr
o
l Mode Con
s
ideri
ng the SO
C Error of ESS
Suppo
sing
2
T
, the value of
is
5
2.5
1
0
accordin
g to the e
q
u
a
tion (12). T
h
e
c
o
ordination
c
ontrol of ESS1 c
o
ns
idering the SO
C error is
shown in Figure 9, in whic
h
“SOC1_A” and “SOC1_Plan” are t
he ac
t
ual SOC and optimal SO
C
of ESS1. The other s
y
mbols
have the
sam
e
meaning
wi
th that in Figure
7. The
coordination
control of ESS2, DG1
and
DG2
are the
same
as that in bia
s
ed n
e
t load
control mod
e
.
Figure 9.
Coordinate Control of
ESS1 Cons
idering the SOC Error
Figure 10.
Power of DG/
ESS with the Coor
dination
Sys
t
em Considering SOC
Error
Figure 11.
Ac
tual SOC of ESS 1 with t
he Co
ordination Sys
t
em C
ons
idering S
O
C Error
Figure 12.
Actual Net Lo
ad of the Net
w
ork wi
th the
Coo
r
din
a
tion
System Con
s
iderin
g SOC
Erro
r
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 23
02-4
046
TELKOM
NI
KA
Vol. 12, No. 4, April 2014: 3230 – 3
239
3238
The actual power of ESS1, 2 and
DG1, 2 with
the coordination system are
shown in
Figure 10, and the SOC of
ESS1 is
s
h
own in Figu
re
11. The operating
s
t
atus of all
DGs
/
ESS is
the sa
me a
s
t
he optimal
st
atus d
u
rin
g
th
e time pe
riod
of [0, 1]. Duri
ng [1, 2] the l
oad
s in
cre
a
ses
and the power of
WG
decreases,
and the powers
of ESS1,2 and
DG1,2 i
n
crease
with the
coordination
control. The
planned power of ESS1
is 0, and the
pl
anned SOC
i
s
0.5. The actual
SOC d
e
cre
a
ses
as th
e di
scha
rgin
g of E
SS1 with the
coo
r
din
a
tion
(as
sh
own
in
Figure 11
). T
he
SOC erro
r is negative, an
d this cau
s
e
an additio
nal
regul
ating compon
ent to redu
ce th
e SOC
error. Th
e di
scha
rgin
g po
wer d
e
crea
se
s with the
reg
u
lating
comp
onent. Durin
g
the time pe
ri
od
[2, 3], the po
wer of loa
d
s
and WG are equal to their planne
d value, and corresp
ondi
ngly the
power of ESS2, DG1,2 decrease to
their planned power. As the
actual SOC of ESS1 is lo
wer
than its planned value, ESS1 char
ge
during [2, 3]
to reduce th
e SOC error, and the charging
power of ESS1 is balanced proportionally
by ESS2, DG1,2 and the
external grid.
The a
c
tual
n
e
t load
of the
netwo
rk
with
t
he coo
r
dina
tion sy
stem
consi
deri
ng S
O
C
error
is sh
own in Figure 1
2
.
6. Conclusio
n
Feede
r Control Erro
r (F
CE
) is p
r
op
osed
in
this pap
er base
d
on th
e different be
tween
the actu
al net
load a
nd the
optimal (plan
ned) net
loa
d
of the di
strib
u
tion line. F
C
E is an i
ndi
ca
tor
of the a
c
tual
operating
stat
us
of th
e n
e
twork, a
nd b
a
s
ed
on
FCE
a co
ordinatio
n co
ntrol
syst
em
is proposed to coordinate the operating of a
ll the D
G
/ESS. 3 coordination control modes
are
proposed: c
o
ns
is
tent net load
control mode, bias
ed net load c
o
ntrol mode and the c
ont
rol mode
c
o
ns
idering t
he SOC error of
ESS. The
c
o
ordi
nation s
y
s
t
em
in the
3
c
o
ntrol modes
are
demon
strated
and verified i
n
the ca
se st
udy.
There are e
rro
rs
betwee
n
the fore
ca
st
ed loa
d
/re
newable e
n
e
r
gy and the
actual
load/re
ne
wab
l
e energy. With the
coordi
nation syste
m
, the unexpect
ed loa
d
a
nd the fluctu
ation
of the renewable energy
will be
balanced
by all the power adj
us
table DGs/E
SS
proportionall
y
according to their coo
r
din
a
tion co
efficien
t, and th
is re
duce the imp
a
ct ca
used b
y
the foreca
st
ing
error an
d the fluctuation
of
the rene
wa
bl
e energy.
Ackn
o
w
l
e
dg
ments
The auth
o
rs
woul
d like to
thank th
e su
p
port of The
National Hi
gh
-tech
R&D P
r
o
g
ram of
Chin
a (86
3
Prog
ram with i
s
sue num
be
r: 2012AA05
0
2
12).
Referen
ces
[1]
JA Peças Lo
pe
s, N Hatziarg
yr
iou, J Mutale,
et al.
Integratin
g distrib
u
ted g
ener
ation i
n
to
electric p
o
w
e
r
s
y
stems: A r
e
v
i
e
w
of driv
ers, chall
e
n
ges
an
d
opp
ortun
i
ties.
Electric
Power System
s Research
. 20
07
;
77(9): 11
89-
12
03.
[2]
Z
e
chun
Hu, F
u
ron
g
Li. C
o
st
-Benefit An
al
yses of Active
Distributi
on
Ne
t
w
ork M
a
n
age
ment, Part I:
Annu
al Be
nefit Anal
ys
is.
IEEE Trans.on Smart Grid
. 2012; 3(3): 1067-
10
74
.
[3]
Z
e
chun H
u
, Furon
g
Li. Cost
-Benefit Ana
l
yses of
Active Distributi
on N
e
t
w
ork Ma
na
ge
ment, Part II:
Investment Reduction Analy
s
is.
IEEE
Trans. on S
m
art Grid
. 201
2; 3(3): 107
5-10
81.
[4]
W
A
NG Cheng
shan, GAO F
e
i, LI Peng, et al.
Control Strategy Res
earch
on Low
Volta
g
e
Micro grid
.
Procee
din
g
s of
the CSEE. 2012; 32(2
5
): 2-8
.
[5]
Il-Yop C, W
e
n
x
in L, Cartes
DA
, et al. Control
met
hods of
inv
e
rter-interfac
e
d
distribute
d
g
e
nerators i
n
a
micro grid s
y
st
em.
IEEE Trans. On Industrial
Applic
ations
. 2
010; 46(
3): 107
8-10
88.
[6]
LIAO Zhi-ling,
RUAN
Xin-
bo
.
Energy Man
age
ment Co
ntrol Strat
egy fo
r Stand-al
on
e Photovo
l
ta
i
c
Power System
.
Proceed
in
gs o
f
the CSEE. 2009; 29(2
1
): 46-
52.
[7]
G
y
a
w
a
li
N, Ohsa
w
a
Y, Yam
a
moto O. Po
w
e
r mana
geme
n
t of dou
ble-fe
d
ind
u
ction
ge
ne
rator-bas
e
d
w
i
nd
p
o
w
e
r s
ystem
w
i
th
inte
grated
smart e
nerg
y
st
orag
e
havi
ng s
uperc
ond
uctin
g
ma
g
netic e
ner
g
y
storage/fue
l
-ce
ll/electr
ol
yser.
IET
Renew
abl
e
Pow
e
r Genera
t
ion
. 201
1; 5(6)
: 407-42
1.
[8]
Li
Xi
an
gju
n
, H
u
i D
o
n
g
, W
u
Li, et
al.
C
ontr
o
l Strate
gy of
Battery St
ate
of Ch
arge
for
W
i
nd/Batter
y
Hybird Power
System
.
Proc
e
edi
ngs
of IEEE Internati
ona
l
S
y
mp
osi
u
m o
n
Industria
l El
ec
tronics. Bari,
Ital
y
. 20
10: 27
23-2
726.
[9]
Moham
ed
A,
Sale
hi V,
Moh
a
mmed
O. Re
ak-T
ime Energ
y
M
a
n
a
g
e
ment
Alg
o
rithm f
o
r
Mitigati
on
o
f
Pulse L
o
a
d
s in
H
y
br
id Micro
g
r
ids.
IEEE Trans. on Sm
art Grid
. 2012; 3(
4): 1911-
192
2.
[10]
Araba
li A, Ghofrani
M, Etez
adi-Am
o
li M, e
t
al. Genetic-A
l
gorit
hm-Base
d
Optimization
Appro
a
ch for
Energ
y
Ma
na
g
e
ment.
IEEE Trans. on Power
Delivery
. 2
013
; 28(1): 162-1
7
0
.
Evaluation Warning : The document was created with Spire.PDF for Python.
TELKOM
NIKA
ISSN:
2302-4
046
Coo
r
din
a
tion
of Distrib
u
ted
Generators a
nd Energy Storag
e Sy
ste
m
s (Yu Wen
p
eng)
3239
[11] T
s
ung-Ying
Le
e.
Operat
i
n
g
Sched
ule
of B
a
tter
y
Ener
g
y
Storage
S
y
ste
m
in
a T
i
me-
o
f-Use
Rat
e
Industria
l User
w
i
th W
i
n
d
T
u
rbin
e Gener
ators:
A Multipa
ss Iteration Part
icle S
w
a
r
m
Optimizatio
n
Appro
a
ch.
IEEE Transactions
on Energy Conversion.
20
07
; 22(3): 774-7
8
2
.
[12]
Abbe
y C, Jo
os
G. A Stochasti
c Optimization
Appr
o
a
ch to R
a
ting of En
erg
y
Storage S
y
ste
m
s in W
i
nd-
Diese
l Isolate
d
Grids.
IEEE
Tr
ans. on Power
System
s
. 20
09
; 24(1): 418
–42
6.
[13]
Pilo F, Pis
ano G, Soma GG. Optimal Coor
dina
tion of Energy
Resource
s
w
i
t
h
a T
w
o-
Stage Onlin
e
Active Mana
ge
ment.
IEEE Tr
ans. on Industrial Electronics
.
201
1; 58(1
0
): 4526-
453
7.
[14]
Cha
o
Chu
ng-
Hsing. A remo
te po
w
e
r ma
n
agem
ent
strateg
y
for the so
lar en
erg
y
p
o
w
e
r
e
d
bic
y
cl
e.
T
E
LKOMNIKA T
e
leco
mmunic
a
tion C
o
mputi
n
g Electron
ics a
nd Co
ntrol
. 20
11; 9(3): 48
3-4
88.
[15]
W
ong J
e
n
n
H
w
a,
Sutik
n
o
T
o
le, Idris
Nik
Ru
mzi Nik. A
p
a
r
a
lle
l
en
erg
y
-sh
a
rin
g
co
ntrol
strateg
y
for
fue
l
cell hy
brid vehicle.
T
E
LKOMNIKA T
e
leco
mmunic
a
tion
Co
mputin
g Electro
n
i
cs an
d Co
ntrol
. 2011; 9(
2):
357-
364.
Evaluation Warning : The document was created with Spire.PDF for Python.