Siemens Siprotec 7VK61 Manual page 88

Functions
2.4 Synchronism and voltage check (optional)
230 Rated Frequency
1103 FullScaleVolt.
and, if closing at asynchronous system conditions is allowed,
239 T-CB close
WARNING!
Closing at Asynchronous System Conditions!
Closing under asynchronous system conditions requires the closing time of the circuit breaker to be set cor-
rectly in the Power System Data 1 (address 239).
Otherwise, faulty synchronization may occur.
General
The synchronism check can only operate if it has been set to Enabled and parameter U4 transformer (ad-
dress 210) to Usy2 transf. during configuration of the device scope (address 135).
The measured values of synchronism check (636 „Udiff =", 637 „Usy1=", 638 „Usy2=", 647 „F-diff=",
649 „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.
The complete synchronism check function is switched ON or OFF in address 3501 FCT Synchronism. If
switched off, the synchronism check does not verify the synchronization conditions and release is not granted.
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-energised (for checking a de-energised 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. De-
pending 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 energised (for energised 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
connection of the voltages 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 pa-
rameterising 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 mon-
itoring 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.
88
the operating range of the synchronism check refers to the nominal frequen-
cy of the power system (f
N
Nominal operational voltage of the primary power system (phase-phase) in
kV;
the closing time of the circuit breaker.
± 3 Hz);
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009