Siemens SIPROTEC 4 7VK61 Manual page 90

Functions
2.4 Synchronism and voltage check (optional)
230 Rated Frequency
1103 FullScaleVolt.
and, if switching under asynchronous system conditions is allowed,
239 T-CB close
!
WARNING
Switching under Asynchronous System Conditions!
Closing under asynchronous system conditions requires the closing time of the circuit breaker to be
set correctly in the Power System Data 1 (address 239).
Otherwise, faulty synchronization may occur.
²
General
The synchronism check can only operate if during the configuration of the device scope (address 135) it has
been set to Enabled and the parameter U4 transformer (address 210) to Usy2 transf..
The measured values of the synchronism check (636
F-sy1 = , 646 F-sy2 = and 648 φdif= ) are only available if the synchronism check is in service.
Different interrogation conditions can be parameterized for automatic reclosure on the one hand and for
manual closure on the other hand. Each closing command is considered a manual reclosure if it was initiated
via the integrated control function or via a serial interface.
The general limit values for synchronism check are set at address 3501 to 3508. Additionally, addresses 3510
to 3519 are relevant for automatic reclosure, addresses 3530 to 3539 are relevant for manual closure. More-
over, address 3509 is relevant for closure via the integrated control function.
At address 3501 FCT Synchronism you switch the entire synchronism check function ON- or OFF. If
switched off, the synchronism check does not verify the synchronization conditions and it finds keine Frei-
gabe. You can also set ON:w/o CloseCmd: The CLOSE command is in this case not included in the common
device alarm Relay CLOSE (No 510); but the alarm Sync.CloseCmd (No 2961) is issued.
Address 3502 Dead Volt. Thr. indicates the voltage threshold below which the feeder or the busbar can
safely be considered de-energized (for checking a de-energized feeder or busbar). The setting is applied in
Volts secondary. This value can be entered as a primary value when parameterising with a PC and DIGSI.
Depending on the VT connection these are phase-to-earth voltages or phase-to-phase voltages.
Address 3503 Live Volt. Thr. indicates the voltage above which the feeder or busbar is regarded as
being definitely energized (for energized line or busbar check and for the lower limit of synchronism check). It
must be set below the minimum operational undervoltage to be expected. The setting is applied in Volts
secondary. This value can be entered as a primary value when parameterising with a PC and DIGSI. Depending
on the VT connection these are phase-to-earth voltages or phase-to-phase voltages.
The maximum permissible voltage for the operating range of the synchronism check function is set in address
3504 Umax. The setting is applied in Volts secondary. This value can be entered as a primary value when
parameterising with a PC and DIGSI. Depending on the VT connection these are phase-to-earth voltages or
phase-to-phase voltages.
Verification of the release conditions via synchronism check can be limited to a configurable synchronous
monitoring time T-SYN. DURATION (address 3507). The configured conditions must be fulfilled within this
time. If not, closure will not be released. If this time is set to ∞ , the conditions will be checked until they are
fulfilled or the measurement request is cancelled.
For switching under synchronous conditions you can specify a delay time T SYNC-STAB (address 3508).
During this time the voltage criteria must at least be fulfilled before closing is released.
90
the operating range of the synchronism check refers
to the nominal frequency of the power system (f
Hz);
nominal operational voltage of the primary power
system (phase-phase) in kV;
the closing time of the circuit breaker.
Udiff = , 637 Usy1= , 638 Usy2= , 647 F-diff= , 649
C53000-G1176-C159-5, Edition 05.2018
±3
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SIPROTEC 4, 7VK61, Manual