ABB Relion REQ650, Руководство по применению

Страница: 218 / 340

In
st
an
t o
f f
au
lt
S
TB
R
R
E
C
re
se
t
Open
Closed
Operate time
Line
protection
Circuit
breaker
Break time
T
rip
c
om
m
an
d
C
on
ta
ct
s
se
pa
ra
te
d
A
re
e
xt
in
gu
is
he
rs
Fault duration STBRREC open time for breaker
Fault duration
R
es
et
s
O
pe
ra
te
s
Break time Closing time
Operate time
Fa
ul
t
O
pe
ra
te
s
R
es
et
s
C
lo
se
c
om
m
an
d
C
on
ta
ct
c
lo
se
d
Set STBRREC open time Reclaim time
Auto-reclosing
function
S
ta
rt
S
T
B
R
R
E
C
R
ec
lo
si
ng
co
m
m
an
d
IEC10000223_1_en.vsd
IEC10000223 V1 EN
Figure 90: Single-shot automatic reclosing at a permanent fault
Single-phase tripping and single-phase automatic reclosing is a way of limiting the
effect of a single-phase line fault on power system operation. Especially at higher
voltage levels, the majority of faults are of single-phase type (around 90%). To
maintain system stability in power systems with limited meshing or parallel routing
single phase auto reclosing is of particular value. During the single phase dead time
the system is still capable of transmitting load on the two healthy phases and the
system is still synchronized. It requires that each phase breaker operates individually,
which is usually the case for higher transmission voltages.
A somewhat longer dead time may be required for single-phase reclosing compared
to high-speed three-phase reclosing. This is due to the influence on the fault arc from
the voltage and the current in the non-tripped phases.
To maximize the availability of the power system it is possible to choose single pole
tripping and automatic reclosing during single-phase faults and three pole tripping and
automatic reclosing during multi-phase faults. Three-phase automatic reclosing can
be performed with or without the use of a synchronicity check, and an energizing
check, such as dead line or dead busbar check.
During the single-pole open time there is an equivalent "series"-fault in the system
resulting in a flow of zero sequence current. It is therefore necessary to coordinate the
Section 10
1MRK 505 291-UEN A
Control
212
Application manual