Functional Sequence
Validity Check of the Configuration
Already during startup of the device, a validation check of the configuration is performed. If there is a fault,
the message
25 Set-Error
is output. after a measurement request there is a condition which is not plau-
sible, the message
25 Set-Error
is output. The measurement is then not started.
Concerning the configuration, it is also checked if the substation parameter 213 is set to Vab, Vbc, VSyn or
Vph-g, VSyn. Furthermore, specific thresholds and settings of the function group are checked. If there is a
condition which is not plausible, the error message
25 Set-Error
is output additionally. Please ensure in
this case that address 6106 (threshold V
1
, V
2
energized) is smaller than address 6103 (lower voltage limit
Vmin). The synchrocheck function cannot be controlled via a binary input.
SYNC Error
The synchronization is not started if a voltage transformer failure (m.c.b. tripping) is communicated to the
device via the binary input 6509
>FAIL:FEEDER VT
or 6510
>FAIL: BUS VT
. The message
25 Sync.
Error
is output. In this case, the synchronization can be controlled directly via a binary input.
In case of a protection pickup, the complete synchronization process is reset instantaneously.
Release
The synchrocheck function only operates if it receives a measurement request. This request may be issued by
the internal control function, the automatic reclosing function or externally via a binary input, e.g. from an
external automatic reclosing system.
Before a release for closing is granted, the following conditions are checked:
•
Is the reference voltage V
1
above the setting value Vmin but below the maximum voltage Vmax?
•
Is the voltage V
2
to be synchronized above the setting value Vmin, but below the maximum voltage
Vmax?
•
Is the voltage difference V
2
– V
1
within the permissible limit dV SYNCHK V2>V1?
•
Is the voltage difference V
1
– V
2
within the permissible limit dV SYNCHK V2<V1?
•
Are the two frequencies f
1
and f
2
within the permissible operating range f
Nom
± 3 Hz?
•
Is the frequency difference f
2
– f
1
within the permissible limit df SYNCHK f2>f1?
•
Is the frequency difference f
1
– f
2
within the permissible limit df SYNCHK f2<f1?
•
Is the angle difference α
2
– α
1
within the permissible limit dα SYNCHK α2>α1?
•
Is the angle difference α
1
– α
2
within the permissible limit dα SYNCHK α2<α1?
If there is a condition which is not plausible, the message
25 Sync. Error
is output and the measurement
is not started. the conditions are plausible, the measurement is started (message
25-1 meas.
) and the
configured release conditions are checked.
Each condition which is met is indicated explicitly (messages
25 Vdiff ok
,
25 fdiff ok
,
25 αdiff ok
).
Conditions which are not met are also indicated explicitly, e.g. when the voltage difference (messages
25
V2>V1
,
25 V2<V1
), frequency difference (messages „25 f2>f1“, „25 f2<f1“) or angle difference (messages
25
α2>α1
,
25 α2<α1
) is outside the limit values. The precondition for these messages is that both voltages are
within the operating range of the synchrocheck function (see “Operating Range”).
If the conditions are met, the synchrocheck function issues a release signal for closing the relay (
25 CloseR-
elease
). This release signal is only available for the configured duration of the CLOSE command and is
processed by the device's function control as CLOSE command to the circuit breaker (see also margin heading
“Interaction with Control”). However, the message
25 Synchron
is applied as long as the synchronous condi-
tions are met.
2.20.2
Functions
2.20 Synchrocheck
SIPROTEC 4, 7SJ80, Manual 263
E50417-G1140-C343-A8, Edition 12.2017
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