Indonesian J
ournal of Ele
c
trical Engin
eering and
Computer Sci
e
nce
Vol. 2, No. 3,
Jun
e
201
6, pp. 530 ~ 53
6
DOI: 10.115
9
1
/ijeecs.v2.i3.pp53
0-5
3
6
530
Re
cei
v
ed Ma
rch 1, 2
016;
Re
vised
Ma
y 17, 2016; Accepted Ma
y 29
, 2016
Mitigation of Voltage Fluctuation in Power Distribution
System using D-STATCOM in Egypt
MA Meh
a
nn
a, SK Elsa
y
e
d and Yahia M Esmail*
Dep
a
rtment of Electrical E
ngi
neer
i
ng, F
a
cult
y of Eng
i
ne
eri
n
g, Univers
i
t
y
of
AL-Azhar, Cai
r
o, Eg
ypt
*Corres
p
o
ndi
n
g
author +
2
0
1
006
50
200
2, en
g_mus
lim1
0
0
@
yah
oo.com
A
b
st
r
a
ct
Electrical
pow
er quality is becom
ing
intensity concerned from both
electric utilities and customers.
Voltage
fluctuation is a major pow
er
quality problem as it has a
signi
ficant impact on both the equipment
and
production environment.
T
h
is w
o
rk describes
the
voltage
control technique of
mitigation of voltage
fluctuations and clearing fault usi
ng distribution static synchronous co
mpensator (DST
AT
COM). T
he
test
system
used is Egyptian
native pow
er distribution
system. A simulation
w
a
s done using MATLAB/Simulink
softw
are.
Ke
y
w
ords
: po
w
e
r quality, vol
t
age fluctu
ation
s
, DST
A
T
C
OM
Copy
right
©
2016 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
The power
quality has
become one
of the
most
focus of
attention in
the power industry
since the late 1980s [1].
Power quality is defi
ned as
any power problem detected in
voltage,
current, or frequency deviations that results in fa
ilure or misdirection of customer equipment
[2].
Voltage fluctuation is the main power qualit
y
regard for both power utility and
customers.
Voltage Fluctuations are defined as a series
of random voltage changes, the magnitude of
which does not normally exceed the voltage ranges spec
ified
by ANSI C84.1 of [ 0.9 to 1.1 ]
per
unit with frequencies
less than 25
Hz and its
typi
cal duration is
intermittent [3].
Voltage
fluctuation at the
load can be
caus
ed by events
at many different
points in the
power system
as
distribution system from
most
consumers,
power generation
and transmission
lines because
of
different
conditions [4]. Voltage fluctuations a
ffect on impressible equipment such as light
sources (flicker), electrical machines, elec
tro-heat equipments and many other troubles [5].
In this paper D-STATCOM was
utilized
to miti
gate voltage fluctuation
in Egyptian
native
power
distribution system. The
DSTATCOM
is a fast respons
e
power quality device, which
installed in the distribution sy
stem for reactive power compensation and mitigation of
voltage
fluctuation
and many
of other power
quality
troubles
such as reducing
Harmonics and power
factor correction [6].
In our work
D-STATCOM is
connected
in shunt with
the main
distribution
line for compensation of voltage fluctuations [7].
DSTATCOM is the best
shunt connected FA
CTS
devices [8]. The
operation of the
D-
STATCOM
is as
follows,the Voltage Source
Conv
erter (VSC)
voltage is compared
with the AC
bus
voltage system, When the AC bus voltage
m
agnitude is above that of the VSC magnitude
voltage; the AC system sees the D-STATCOM
as
inductance connected to its terminals and
it
absorbs
the increasing
of nominal voltage.
Also
, if
the VSC voltage
magnitude is
above that of
the AC bus voltage
magnitude, the AC system
sees the D-STATCOM as
a capacitance to
its
terminals and injecting require voltage. If the
voltage magnitudes are equal, the reactive
power
exchange
is zero [9]. In this paper the
te
st and simulation of DSTATCOM are using
MATLAB/SIMULINK software in
order to
regulat
e and
mitigate voltage
fluctuations on
Egyptian
native
power distribution system. In this
paper the system was te
sted with and without
DSTATCOM at many
cases such
as
fluctuated source, fluctuated
load, fault
occurrence and
all
of
this cases together in order to mitigate
voltage and display a high response of DSTATCOM
for mitigation voltage fluctuations and clearing faults.
Evaluation Warning : The document was created with Spire.PDF for Python.
ISSN: 25
02-4
752
IJEECS
Vol.
2, No. 3, Jun
e
2016 : 530
– 536
531
2. Methodol
og
y
and Model Desc
ripti
on
DSTATCOM is used to regulate voltage
on a 22-KV real Egyptian native
power
distribution system. The structur
e of DSTATCOM and
its equivalent circuit is shown in figure
1
[10].
The D-STATCOM regulates
voltage by absorbing
or injecting reactive
power. This reactive
power transfers through the
leakage reactance
of the
coupling transformer. The
D-STATCOM
consists of the following com
ponents as shown in figure 1:
A 22 kV/1.25
k
V cou
p
ling transfo
rme
r
wh
ich
en
su
re
s couplin
g between the PWM
inverter
and the net
work.
A voltage-sou
r
ce
d PWM
co
nverter
con
s
i
s
ting of
two IGBT brid
ges.
This twin inv
e
rter
config
uratio
n prod
uces fe
wer ha
rmoni
cs than a sin
g
le
bridg
e
LC dam
ped fi
lters
conn
ect
ed at the inverter
outp
u
t. Resi
stan
ce
s co
nne
cted in se
ries
with
cap
a
cit
o
rs.
A 10000
-microfarad
cap
a
ci
tor rep
r
e
s
ent
s a DC voltag
e sou
r
ce for the co
nverte
r
A PWM pulse
generator.
Anti-alia
sing f
ilters u
s
ed fo
r voltage and
curre
n
t acq
u
i
s
ition.
DS
TA
TC
OM
cont
r
o
l
sy
st
e
m
Figure 1. (a)
Structu
r
e of DSTA
TCOM,
(b) Equivale
nt circuit
Figure 2. Simulink mo
del o
f
DSTATCO
M
comp
one
nts.
In our work, part of
real Egyptian native
power distribution
sy
stem was studied
for
utilizing DSTATCOM
to regulate
voltage on
a 22-KV
our
distribution
network as
shown in
figure.
Two feeders (21 km and 2 km) transmit power to l
oads at buses B2 and B3.
A shunt capacitor is
used for power factor correction at bus B2. T
he load is equivalent to a section of
medium
Evaluation Warning : The document was created with Spire.PDF for Python.
IJEECS
ISSN:
2502-4
752
Mitigation of Voltage Flu
c
tuation in PDS
using
D-STA
T
COM in Eg
ypt
(Yahia M E
s
m
a
il)
532
voltage distribution
panel (22
KV) where
the feeders
come out
as shown
in figure
4.3. One
of
these feeders represents the (400-V
and 2MW) load of
the
factory which it and its
distribution
panel connected to bus B3 through a 22kV/400V, 4
MVA transformer. The factory is
producing
voltage fluctuations and flicker. This factor
y
connected to the distribution panel through
a
22kV/400V, 4 MVA transformer. This distributi
on panel
connected to bus B3. The variable
load
current magnitude of the factory is modulated at
a frequency of 5 Hz while keeping a
0.9
lagging
power factor. The run time for the w
hole system is half second (0.5 s).
Then
we test the system with and without
DSTATCOM at many cases such as
fluctuated source,
fluctuated load,
fault
occurrenc
e and
all of
this cases together
in order to
mitigate voltage and display a high response of DS
TATCOM for mitigation voltage fluctuations.
Figure 3. Part of real Egyptian native po
wer di
stri
buti
on syst
e
m
wit
h
DSTATC
O
M
Table 1. The
para
m
eter val
ues of the sy
stem
Parameters
Val
ues
Source voltage
Source Po
w
e
r
Line Length
Coupling transfor
m
er
DSTATC
OM v
a
l
ue
Distribution Power Tr
ansforme
r
Reference Volta
ge of DSTA
TC
OM
22KV/ 50Hz
100MVA
23 Km
22 kV/1.25kV
3.5 MVAR
4 MVA
1 pu
3. Result and Discussion
In this term we test and simulate DSTA
TCOM using MATLAB/SIMULINK software
in
order to mitigate voltage fluctuations on 22-kV r
eal Egyptian native power
distribution system
as
shown in figure 3. The simulation time is one second.
In this simulation we test the system with
and without DSTATCOM at many
cases such as fluctuated s
ource, fluctuated load,
fault
occurrence and all of this cases together. DSTA
TCOM used in this simulation +/- 3.5 MVAR.
3.1. Test Sy
stem
at Fluctuated Source Only
In this case, the system without and with
installing DSTATCOM is displayed
when
voltage
fluctuation comes from supply
(sources)
and display the
effect of inserting DSTATCOM
on voltage quality of the distribution
system as shown in figure 4,5.
At t =
0.2 s,
the source voltage
is incr
eased
by 7%. The
D-STATCOM compensates
for
this voltage increase
by absorbing r
eactive
power from the
network (Q =
+2.9 MVAR). At
t =
0.3
s,
the source voltage
is decreased by 7%.
T
he D-STATCOM must
generate reactive power to
maintain
a (1 pu) voltage (Q changes from +2.9
MVAR to -3.4 MVAR). Note that when the D-
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ISSN: 25
02-4
752
IJEECS
Vol.
2, No. 3, Jun
e
2016 : 530
– 536
533
STATCOM changes from
inductive to
the capacitiv
e operation,
the reversing
of reactive
power
is
very fas
t.
Figure 4. Terminal Voltage
at load buse B3 without DSTATCOM
Figure 5. Terminal Voltage
at load buse
s
with DSTAT
C
OM
3.2. Test Sy
stem
at Fluctuated Load Only
In this case, the system without and with
installing DSTATCOM is displayed
when
voltage
fluctuation comes from customer load
only.
And show the effect of inserting
DSTATCOM to
mitigate voltage
fluctuations result
ing
from fluctuated
load bus
B3 as
shown
in
figures
6,7. In this case
the reactive power
of
DSTATCOM’s compensation changed from +1.6
MVAR to -2.3 MVAR to mitigate volt
age fluctuations by the high response.
Figure 6. Terminal Voltage
at load buse
s
witho
u
t DSTATCOM
Evaluation Warning : The document was created with Spire.PDF for Python.
IJEECS
ISSN:
2502-4
752
Mitigation of Voltage Flu
c
tuation in PDS
using
D-STA
T
COM in Eg
ypt
(Yahia M E
s
m
a
il)
534
Figure 7. Terminal Voltage
at load buse B3 with DST
A
TCOM
3.3. Clearing Three Phase Fault to Ground
In
this case the
transient fault occurs bet
ween
0.1 s to
0.2 s. The 3-ph
to a ground fault
by a fault resistance of 79
Ω
which affects the load voltage st
ability at B3. DSTATCOM acts a
capacitor which compensates this voltage decrease
by injecting reactive power by (- 3.3 MVAR)
at time 0.1 s to 0.2 s and clearing transient faul
t as shown in Figure as shown in figure 8,9.
Figure 8. Terminal Voltage
at load buse
s
witho
u
t DSTATCOM
Figure 9. Terminal Voltage
at load buse
s
with DSTAT
C
OM
3.4.
Test Simulation Sy
stem
at Fluctuat
ed Source and
Fluctuated Load Apply
i
ng Three
Phase Fault to Ground Together
This case considers a worst case. In this
case the voltage at load fluctuates
between
(1.06
to 0.92) pu. The system
without and
with installing DSTA
TCOM is displayed during the
occurrence of
all cases
mentioned above
toget
her.
Displaying the
effect of
installing
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ISSN: 25
02-4
752
IJEECS
Vol.
2, No. 3, Jun
e
2016 : 530
– 536
535
DSTATCOM on voltage fluctuation
mitigation of t
he distribution
system as shown in
figures
10,11. The compensated Reactive Power (MVAR)
by DSTATCOM as follow, DSTATCOM
acts
a
capacitor which compensates voltage decrease
wh
ich it caused by a transient 3-ph fault to
ground- by injecting reactive power (- 3.3
MVAR) at
time 0.1 s to 0.2
s. At t = 0.2 s, the
voltage
is increased by
6%. The
D-STATCOM compensat
es for
this voltage
increase by
absorbing
reactive
power from the
network (Q =
+2.6 MVAR
). At
t = 0.3
s, the source
voltage is decreased
by 8%. The D-STATCOM must generate reactive
power to maintain a (1 pu) voltage
(Q
changes from
+2.6 MVAR
to -3.3
MVAR). Note
that
when the
D-STATCOM response
is very
fast where between (3-6) msec.
Figure 10. Te
rminal Voltag
e at
load bu
se B3 without DSTATCOM
Figure 11. Te
rminal Voltag
e at load bu
se B3 with DS
TATCOM
4. Conclusion
In this pape
r
D-STAT
COM
is use
d
to mitigate
voltage
fluctuation a
nd flicker in E
g
yptian
native po
we
r distri
bution
system
. T
h
is pape
r p
r
e
s
e
n
ts a fa
st re
spo
n
se rea
c
tion by u
s
ing
D-
STATCOM
to
overcom
e
v
o
ltage flu
c
tua
t
ions i
n
comp
arison to
oth
e
r FA
CTS
de
vic a
s
sho
w
n
in
previous figures. After reviewin
g this
paper you
have
the ability to
define voltage Fluct
uation
and
overcome vo
ltage fluctuati
on problem
s in your
nati
v
e powe
r
di
stribution n
e
twork with lat
e
st
techni
que
s.
Referen
ces
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an, MF
McGranagh
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IJEECS
ISSN:
2502-4
752
Mitigation of Voltage Flu
c
tuation in PDS
using
D-STA
T
COM in Eg
ypt
(Yahia M E
s
m
a
il)
536
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