2010 International Conference on Power System Technology
Investigation ofTRV across Circuit-breaker of
Series compensated Double-circuit URV
Transmission Lines
Zutao Xiang, liming Lin, Liangeng Ban, Bin Zheng
Huainan
Wannan
Zhebei
Huxi
Abstract--State Grid Corporation of China plans to build the
Huainan-Wannan-Zhebei-Huxi UHV double-circuit transmission
project and install series capacitors (SCs) in Huainan-Wannan
transmission lines. During the circuit breakers clearing system
�1!-=340k::!-jml-
���,""Q
faults on series compensated transmission line, the transient
recovery voltage (TRV) of circuit breaker may be increased due
to the impact of series capacitor. If there is no countermeasure,
the TRV may higher than the limit in circuit breaker standard.
This phenomenon may result in the failure of clearing system
fault and the damage of circuit breaker. This paper investigated
the influences of series capacitor on TRV. In order to limit the
TRV, the fast bypass series capacitor based on system protection
and relay system is suggested.
Index Terms-- Switching transients, Capacitor compensated
transmission lines, UHV transmission
I. NOMENCLATURE
TRV -Transient Recovery Voltage
RRRV - Rate of Rise of Recovery voltage
II. INTRODUCTION
SGCC (State Grid Corporation of China) plans
to build the Huainan-Wannan-Zhebei-Huxi UHV double­
circuit transmission project and install series capacitors (SCs)
in Huainan-Wannan transmission lines (as fig. 1).
CEPRI (China Electric Power Research Institute) are
carrying on a series of studies for this project under the
supporting of SGCc. The transient characteristic of 1lOOkV
circuit breakers is one of the important topics of these studies,
as the circuit breaker is one of the most important devices in
UHV Grid and there are remarkable manufactural difficulties
[6], and the TRV of circuit-breaker may be influenced by the
2
series capacitor in the transmission line [I] [ ] [5]. This paper
mainly focuses on the TRV research of series compensated
UHV transmission line.
I
N 2010,
This work was supported by State Grid Corporation of China.
Zutao Xiang, liming Lin, Liangeng Ban and Bin Zheng work in the
Department of Power System, China Electric Power Research Institute,
Beijing, China (e-mail xzt@epri.sgcc.com.cn. jmlin@epri.sgcc.com.cn.
banlgeng@epri.sgcc.com.cn, zhengbin@epri.sgcc.com.cn).
978-1-4244-5940-7/10/$26.00©2010 IEEE
Fig. 1. Huainan-Wannan-Zhebei-Huxi 1000kV UHV Transmission system
III. EFFECTS OF SERIES COMPENSATION ONTRV
Clearing system fault is a basic function of circuit breaker.
The transient recovery voltage (TRV) is the voltage between
the contactors of circuit breaker appearing after the extinction
of the arc between the contactors during opening. It is a key
factor determining whether the circuit breaker can clear the
fault successfully.
Table 1 lists the requirements about TRV of UHV circuit
breaker in Chinese standard GB/Z 24838-2009. Up to now,
the TRV of UHV circuit breaker hasn't been added into
related IEC standards. However, the requirements about TRV
in GB/Z 24838-2009 are similar with the extensions of the
TRV requirements in IEC 62271-100[4]. In table I, the
maximum peak value of TRV is 2245 (2.5 p.u.,
Ip.u.=1100 x V2/V3kV), which defined for opposite phase
test.
TABLE I
REQUIREMENTS ABOUT TRV OF UHV CIRCUIT BREAKER IN CHINESE
STANDARD GB/Z 24838-2009[31
Rated Voltage
U,
(kV)
1100
TRV peak Value
Type of Test
Ue
kV
RRRV·
u/t1
Uclt3
kV/us
TIOO
1635
T60
1751
3.0
T30
1786
5.0
TIO
1786
7.0
OPI-OP2
2245
1.54
2.0
*RRRV Rate of Rise of Recovery voltage
If system fault occurs in a series compensated transmission
line. The series capacitor may be bypassed when the short
circuit is significant larger than the rated current of series
capacitor. At this case, the TRV of circuit breaker would not
be influenced by the series capacitor obviously. But if the
fault current is not very large (especially when the fault occurs
far away from the capacitor), the series capacitor would not be
bypassed. As shown in fig. 2, the TRV ( UTRV ) of circuit
2
breaker Kl is the results of its bus side voltage ( UKE ) minus
the line side voltage ( UKL ) , and UKL is equal to the sum of
the voltage at the line end ( UL ) and the voltage of series
capacitor (uc). As the present of series capacitor, the TRV
may much higher than TRV in non series compensated lines.
"
Ii
\, ...
�
'±
K,t--e
Fault
lie
Fig. 2. Effects of Series Compensation on TRY
IV. THE ANALYSIS OFTRV IN HUAINAN-WANNAN SERIES
COMPENSATED SYSTEM
At the planning stage of the Huainan-Wannan UHV
double-circuit transmission system, the rated parameters and
the install location of series capacitors haven't been decided
yet. So, in this research, the TRV research conditions were
assumed as follows [I] [9]:
(I) Series compensation degree of Huainan-Wannan UHV
transmission line is 40%.
(2) Two schemes about install location are considered. One
is all the series capacitor of 40% compensation degree is
installed at Huainan, and the other is that the capacitor is
dived into two same segments and they are separately installed
at Huainan and Wannan as fig. I (presented as 20%+20%).
(3) There are shunt compensation at the both terminals of
the Huainan-Wannan UHV line. Based on the consideration of
voltage profile along the transmission line, the series
capacitors are installed at the line side of shunt reactor.
(4) Present and long-range prospective system conditions
are considered.
(5) The power flow is considered as up to 1000MW.
(6) The rated current of capacitor is considered as 6000A.
(7) M-type overvoltage protector for series capacitor is
used, shown as fig.3.
(8) Single phase to ground (lLG) and three phases to
ground (3LG) fault are considered at this paper, other types of
faults will be considered in the next stage research.
(9) Different fault places along the transmission line are
considered.
(10) Probabilities of the fault occurring instant and duration
time.
The calculated results of TRV of circuit breakers in
Huainan-Wannan double-circuit UHV transmission line are
shown in fig. 4 to fig. 7 and table 2. The results are discussed
in the follows:
(1) The TRV of breaker of series compensated
transmission line is observably larger than that of transmission
line without series capacitor, as shown in figA and fig.5.
(2) As the waveform shown in fig. 8, when the series
capacitor is installed at Huainan only, the TRV of Huainan
breaker during clearing 1LG is up to 2.6p.u. (2328kV), which
is larger than the allowable TRV in table I (2.5p.u.). During
clearing 3LG fault, the TRV may be much larger than the
allowable value, which up to 3.0p.u .. As all the capacitor is
installed at Huainan substation, the TRV of Wannan breaker
hardly affected by series capacitor and it is in the allowable
scale.
(3) When the series capacitors are installed at Huainan and
Wannan (20%+20%), the TRVs of Huainan and Wannan
breakers are both influenced by series capacitor. During
clearing lLG, the maximum peak value of TRV is 2137kV.
As the peak value is less than 2.5 p.u., the RRRV is less than
1.54kV/us and the breaking current is less than 25% of rated
breaking current, it's allowable. During clearing 3LG fault,
the TRV may larger than the allowable value, which up to
2. 8p.u..
(4) When the series capacitor is installed at Huainan only,
the maximum value of TRV is larger than the capacitors are
separately installed at Huainan and Wannan, although the
TRV of Wannan breaker may be larger when the capacitors
are installed at two substations, as shown in fig. 6 and fig.7.
�
�
255km
Wannan
woo lr===�======�
_ without SC, 1 LG
- without SC, 3LG
2500
--
_
2000
--
-'
--
20%+20%, 1 LG
C_-_-_-___-_-J 20%+20%, 3LG
Capacitor
1000
500
Damping
MOV
Gap
Bypass Circuit Breaker
Fig. 3. Metal oxide varistor (MOY) with by-pass gap
o
Huainan
85km
170km
Fault Location
Fig. 4. TRY of Huainan Circuit Breaker of Huainan-Wannan UHY Line with
or without Series Capacitors
3
� r---�--�--���====�
_ without SC, 1 LG
_ without SC, 3LG
20%+20%, 1 LG
L-_-_-_-_-_-_-_-J 20%+20%, 3LG
2500
2000
O
1 ()()()
500
o
o
Huainan
85km
170km
255km
Wannan
Fault Location
Fig. 5. TRV of Wannan Circuit Breaker of Huainan-Wannan UHV Line with
or without Series Capacitors
======��--�--�--�
���
_ 40%, 1 LG
� _40%,3LG
c- 20%+20%, 1 LG
2500
C-_-_-_-_-_-_! 20%+20%, 3LG
3500
�2OOO
:>
� 1 500
1 ()()()
500
o
Huainan
85km
170km
255km
Wannan
Fault Location
Fig. 6. TRV of Huainan Circuit Breaker of Huainan-Wannan Series
Compensated UHV Line with Different Install Locations
3500 r---�--�----�==�======�
_ 40%, 1 LG
_40%,3LG
�
_ ____
20%+20%, 1 LG
� 2000
:>
� 1 500
1 ()()()
500
Huainan
85km
170km
255km
Wannan
Fault Location
Fig. 7. TRV of Wannan Circuit Breaker of Huainan-Wannan Series
Compensated UHV Line with Different Install Locations
TABLE II
MAXIMUM OF TRV PEAK VALUE AT HUAINAN-WANNAN SERIES
COMPENSATED TRANSMISSION SYSTEM
Circuit
Breaker
Huainan
Wannan
.300000
·600000
5E+006
750000
�
1\
f\
�v
t
r--..
J'<
'
,
"
�q
�
(4) Voltage (V) at Line Side ofHuainan Breaker
/\ f\VA�V�
A A ft
.
.
IJ\J\;;;J\)
yo -.-. Vvvuo '\0
V
·750000
o
5E+006
2E+006
600000
O
�������r-��
·600000
2E+006
(6) Recovery Voltage (V) ofHuainan Breaker
6E+006
4E+006
2E+O06�
�0\
�.� ��
�� ����
0r
'V
V
2E+006
1
C"",nt (A) ofH"""""Bre""
1
__________________
=)
[j
�O h
[ ::YY7 ?v :
_i����O.O
100.0
130.0
160.0
190.0
�
220.0
B1f8J(ms)
Fig. 8. TRV and related waveforms when series capacitor is installed at
Huainan and lLG occurred at 255km away from Huainan
Y. THE COUNTERMEASURES FOR THE TRY PROBLEM IN
HUAINAN- WANNAN SERIES COMPENSATED SYSTEM
2500
o
930000
Itage (V) at line for 255km away fromHuainan
465000
0�4-��=-�=-=-----�
·465000
·930000
4E+006
700000
����-+��r-���-+����
·700000
4E+006
600000
(3) Voltage ) of Series Capacitor
300000
,-....
�
Fault
Type
40% SC
at Huainan
20% SC at Huainan
+20% SC at Wannan
lLG
2.6
2.4
3LG
3.0
2.8
lLG
2.0
2.0
3LG
2.5
2.7
In order to decrease the TRY, there are several
8
countermeasures have been discussed [1] [5] [7] [ ]:
(1) Fast bypassing series capacitor with force triggering
GAP based on transmission line relay system.
(2) Decreasing the minimum breakdown voltage of GAP.
(3) Decreasing the compensation degree of series capacitor.
(4) Installing separately the capacitors at two terminals of
the transmission line,
(5) Decreasing the rated current of series capacitor.
(6) Decreasing the protection level of series capacitor.
(7) Increasing the withstanding capability for TRY of
circuit breaker,
(8) Using the circuit breaker with opening resistor.
(9) Install arrestor parallel with the contactors of circuit
breaker.
(10) Using new type device of fast bypassing series
capacitor, such as the Fast Protective Device (FPD) developed
by ABB.
4
As its effectiveness and ease of use, the fast bypass series
capacitor with force triggering GAP method is suggested.
Detail of this method is: When the protection relay system of
transmission line detected the system fault, a bypass signal is
sent to the protection system of the series capacitor, and the
capacitor's protection commands its GAP to trigger at once. If
the condition of triggering of GAP is satisfied at this
procedure, the capacitor can be bypassed in several
milliseconds. This method has been used in many EHV series
compensated systems.
With this fast bypass series capacitor method, the
calculated results of TRV of circuit breakers in Huainan­
Wannan double-circuit UHV transmission line are shown in
fig. 9 and fig. 10. In this section, only the condition of
capacitors being installed at two substations (20%+20%) is
considered. The results are discussed in the follows:
(1) When the system faults occur at the range of 85km to
255km away from Huainan, the fast bypass series capacitor
method can decrease the peak value of TRV obviously. While
this method is used, the typical TRV and related waveform is
as fig. 11.
(2) When the system faults occur at near or far away from
series capacitor, the effects of this method may be less. The
reasons are as bellow:
A. When the system faults position is very close to the
substation with series capacitor, the short current through
series capacitor is very large, and the capacitor quickly
bypassed by its protection system. At this condition, the TRV
is not very large.
B. When the system faults position is far away from
substation with series capacitor, the short current through
series capacitor is not very large, and the overvoltage of
capacitor is not very large either. At this voltage scale, the
GAP couldn't be triggered. So, this method couldn't influence
the maximum peak value of TRV of Huainan breaker when
the fault occurred near Wannan. Whether it has influences at
probabilities ofTRV will be researched in the next stage.
3000
_1LG
2500
>
.><
:>
e:
_ 1 LG-FT
Huainan
�
����8 1 \JV�
\_/ \TV
(2) J..oltage LV) at line �
O
.700000
4E+006
.6 f\ r
1
5E+006
75000 0
0
.750000
5E+006
85km
1 70km
255km
Wannan
+
>
(4) Voltage (V) at Line Side ofHuainan Breaker
J\ f\� A flJ"l..flnf\AII
VVv V-,W'-.../
..I
\.v
o· 0
D'
>
2E+006
600000
O��+-�����
·600000
2E+006
�
Huainan
\ f\�_�Y'ij
..... i\ flflAQ
v�... .(\,
o ����+--+���
-300000
·600000
j
(6) Recovery Voltage (V) ofHuainan Breaker
� .M f
���
(1) Cuneo! (A) ofHuainan Breoke,
r=:vsP:vSl:
-8000
-1600 0.0
0
f series capacitor
600000
300000
1!��1
500
Wan an
930000
ltage (V) at line for 255km away from Huainan
465000
O��������----�--�
·465000
·930000
�
1000
255km
Fig. 10.
TRY of Wannan Circuit Breaker of Huainan-Wannan Series
Compensated UHY Line with or without Force Triggering (FT) GAP
2E+OO
1500
170km
Fault Location
6Et{)06
4E+006
2E+006
2000
85km
U
100.0
130.0
160.0
190.0
�
220.0
B1f8J(ms)
Fault Location
Fig. 9. TRY of Huainan Circuit Breaker of Huainan-Wannan Series
Compensated UHY Line with or without Force Triggering (FT) GAP
Fig. 11. TRY and related waveforms when series capacitor is installed at
Huainan with force triggering GAP and 1LG occurred at 255km away from
Huainan
5
VI. CONCLUSION
State Grid Corporation of China plans to build the
UHV
Huainan-Wannan-Zhebei-Huxi
double-circuit
transmission project and install series capacitors (SCs) in
Huainan-Wannan transmission lines. The TRVs across circuit­
breaker of series compensated UHV transmission lines are
investigated in this paper. The conclusions are as following:
(1) The peak value of TRV of breakers in series
compensated transmission line is observably larger than that
of transmission line without series capacitor, and maybe larger
than the maximum peak value provided in related circuit
breaker standards.
(2) Comparing with the capacitors are separately installed
at Huainan and Wannan, the maximum value of TRV when
the series capacitor is installed at Huainan only is significant
larger.
(3) The method of fast bypassing series capacitor with
force triggering GAP based on transmission line relay system
can decrease the peak value of TRV obviously. So it is
suggested.
Above the discussions mentioned in this paper, deep
researches such as the probabilities of risky TRV are
processing.
IX. BIOGRAPHIES
Zutao Xiang was born in Chongqing, China, in 1976.
He received his bachelor and doctor degrees of
electrical engineering from Tsinghua University in
1999 and 2005. He has been working in the Power
System Department, China Electric Power Research
Institute since 2005. His research focuses on electro­
magnetic transients and FACTS of power system.
Jiming Lin was born in Fujian, China, in 1940. He
graduated from Department of Electrical Engineering
of Tsinghua University in 1964. He worked in High
Voltage Department, China Electric Power Research
Institute from 1964 to 1982. After 1982, he has been
working in the Power System Department
Liangeng Ban was born in China in 1960. He
received his master degree from China Electric Power
Research Institute in 1997. He has been working in
China Electric Power Research Institute and his
research focuses on electro-magnetic transient
analysis of power system.
VII. ACKNOWLEDGMENT
The authors gratefully acknowledge State Grid Corporation
of China for its support.
VIII. REFERENCES
[I]
[2]
[3]
[4]
B. Khodabakhchian, S. Breault, and E. Portales, "TRV and the Non-zero
Crossing Phenomenon Hydro-Quebec's Projected 735 kV Series
Compensated System, " in Proc. 1992 ClGRE Session, 13-303.
Series Capacitors for Power Systems - Part 1: General, IEC Standard
60143-1, 2004.
Specification for 1I00kV alternating-current high-voltage circuit­
breakers, GB/Z 24838-2009 of China
High-voltage Switchgear and controlgear - Part 100: Alternating­
current Circuit-breakers, IEC Standard 62271-100, 2008.
[5]
[6]
[7]
[8]
[9]
P.M. Anderson, and R.G. Farmer, Series Compensation of Power
Systems, California: PBLSH! Inc., 1991
LIN liming, GU Nihong, WANG Xiaogang, XIANG Zutao, BAN
Liangeng, WANG Chengyu, SUN Gang, ZHENG Bin, 'The Transient
Characteristics of II00kV Circuit Breakers, " in Proc. 2007lEC/ClGRE
UHV Symposium, 2-4-4.
B. L. Avent D.F. Peelo and I.H. Sawada, "Application of 500 kv Circuit
Breakers on Transmission Line with MOV Protected Series Capacitor
Bank, " in session 2002 ClGRE.
B. L. Avent D.F. Peelo and lH. Sawada, "TRVs across Circuit Breakers
of Series Compensated Lines. Analysis, Design and Operation
Experience in the 420kv Turkish Grid, " in session 2002 ClGRE.
Shrif Omar Faried and Saleh Aboreshaid, "Stochastic Evaluation of
Transient Recovery Voltages Across Circuit Breakers of Series
Capacitor Compensated Transmission Lines, " IEEE Trans. Power
Delivery, vol. 16, pp. 33-37, Jan. 2001.
Bin zheng was born in China in 1982. He received his master degree from
North China Electric Power University in 2006. He has been working in
China Electric Power Research Institute and his research
focuses on electro-magnetic transient analysis of power
system.