Siemens SIPROTEC 7SS522 V4.6, Руководство пользователя

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Checks With Secondary Values
281
7SS52 V4 Manual
C53000-G1176-C182-3
On the trip characteristic is valid | I
2
−
I
1
|
=
k [| I
1
|
+
| I
2
|]
Because the currents I
1
and I
2
have a phase displacement of 180°, you have
I
2
(1
−
k)
=
I
1
(1
+
k) or. I
2
=
I
1
(1
+
k) / (1
−
k) and
I
2
=
9
×
I
1
, if k = 0,8
‰ Repeat the checking with a different constant current I
1
. The Trip characteristic
graph is shown in Figure 7-12, page 281.
‰ After the checking, switch on the differential current supervision again with the pa-
rameter
DIFF SUPERV
(
6306
/
CU
).
Figure 7-12 Trip characteristic of the busbar protection
7.4.2.2 Check Zone
Alternatively, the decision to trigger by the checkzone can be requested via the mes-
sage "
Trip L1 CZ
" (
FNo. 10457 to 10459/CU
) as a phase selection. This enables
a check which is independent of the selected bus protection.
Example You want to set the trip characteristic for the check zone with the parameters for the
differential current threshold
Id> CZ
(
6104
/
CU
) = 2,0 I
no
and the stabilizing factor
STAB FAC:CZ
(
6103
/
CU
) = 0.8 .
You want to set the busbar-selective protection the parameters
Id> BZ
(
6102
/
CU
) to
0,5 I
no
and the stabilizing factor
STAB FAC:BZ
(
6101
/
CU
) to 0.5 .
Test setup ‰ For the test setup use three bays with the same normalizing factor. Sectionalizers,
or bus couplers must not be used for testing.
‰ Connect the bays 1 and 2 to the same bus zone.
‰ Connect the current inputs of these bay units back to back (see Figure 7-13, page
282). Connect bay 3 to a different bus.
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