Siemens siprotec 7SD5, User Manual

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2.5 Distance Protection
147
7SD5 Manual
C53000-G1176-C169-1
Controlled Zone
Z1B The overreaching zone Z1B is a controlled zone. The normal zones Z1 to Z5 are not
influenced by Z1B. There is therefore no zone switching, but rather the overreaching
zone is activated or deactivated by the corresponding criteria. In address
1651 Op.
mode Z1B
=
Forward
, it can also be switched
Reverse
or
Non-Directional
. If
this stage is not required, it is set to
Inactive
in address
1651
. The setting options
are similar to those of zone Z1: address
1652 R(Z1B) Ø-Ø
, address
1653 X(Z1B)
,
address
1654 RE(Z1B) Ø-E
. The delay times for single-phase and multiple-phase
faults can again be set separately:
T1B-1phase
(address
1655
) and
T1B-multi-
phase
(address
1656
). If parameter
Op. mode Z1B
is set to
Forward
or
Reverse
,
a non-directional trip is also possible in case of closure onto a fault if parameter
1532
SOTF zone
is set to
Z1B undirect.
(see also Section 2.5.1.4).
Zone Z1B is usually used in combination with automatic reclosure and/or teleprotec-
tion systems. It can be activated internally by the teleprotection functions (see also
Section 2.7) or the integrated automatic reclosure (if available, see also Section 2.15),
or externally by a binary input. It is generally set to at least 120 % of the line length.
On three-terminal line applications („teed feeders“), it must be set to securely reach
beyond the longest line section, even when there is additional infeed via the tee point.
The delay times are set in accordance with the type of application, usually to zero or
a very small delay. When used in conjunction with teleprotection comparison
schemes, the dependence on the fault detection must be considered (refer to margin
heading „Distance Protection Prerequisites“ in Section 2.7.14.
If the distance protection is used in conjunction with an automatic recloser, it can be
determined in address
1657 1st AR -> Z1B
which distance zones are released prior
to a rapid automatic reclosure. Usually the overreaching zone Z1B is used for the first
cycle
1st AR -> Z1B
=
YES
). This may be suppressed by changing the setting of
1st AR -> Z1B
to
NO
. In this case the overreaching zone Z1B is not released before
and during the 1st automatic reclose cycle. The zone Z1 is always released, unless it
is blocked by a binary input or in differential protection mode. The setting only has an
effect when the service condition of the automatic reclose function is input to the
device via binary input
„>Enable ARzones“
(No. 383).
The zones Z4 and Z5 can be blocked using a binary input message 3619
„>BLOCK
Z4 Ph-E“
or 3620
„>BLOCK Z5 Ph-E“
for phase-earth loops. To block these zones
permanently for phase-earth loops, said binary inputs must be set to the logic value of
1 via CFC.
2.5.2.3 Settings
Addresses which have an appended "A" can only be changed with DIGSI, under Ad-
ditional Settings.
The table indicates region-specific presettings. Column C (configuration) indicates the
corresponding secondary nominal current of the current transformer.
Addr. Parameter C Setting Options Default Setting Comments
1601 Op. mode Z1 Forward
Reverse
Non-Directional
Inactive Forward Operating mode Z1
1602 R(Z1) Ø-Ø 1A 0.050 .. 600.000
Ω
1.250
Ω
R(Z1), Resistance for ph-
ph-faults
5A 0.010 .. 120.000
Ω
0.250
Ω
1603 X(Z1) 1A 0.050 .. 600.000
Ω
2.500
Ω
X(Z1), Reactance
5A 0.010 .. 120.000
Ω
0.500
Ω
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