Setting Notes - Siemens Siprotec 7VK61 Manual

Closing under asynchronous system conditions
Before releasing a closing command at asynchronous conditions, the following conditions are checked:
• Is the busbar voltage above the setting value Live Volt. Thr. but below the maximum voltage Umax?
• Is the feeder voltage above the setting value Live Volt. Thr. but below the maximum voltage Umax?
• Is the voltage difference |U
maxVolt.Diff?
• Are the two frequencies f
• Does the frequency difference |f
maxFreq.Diff?
When the check has been terminated successfully, the device determines the next synchronizing time from the
angle difference and the frequency difference. The close command is issued at synchronization time minus the
operating time of the circuit breaker.
Measured Values
The measured values of the synchronism check are displayed in separate boxes for primary and secondary
measured values and percentages.
The following is displayed:
• Value of reference voltage U
• Value of the voltage to be synchronized U
• Frequency values f
• Differences of voltage, frequency and angle between U
The primary measured values of the synchronism check are summarized in one of the preset default displays
(see Appendix A.4).
2.4.2

Setting Notes

Preconditions
When setting the general power system data (Power system data 1, refer to Section 2.1.3.1) a number of pa-
rameters regarding the measured quantities and the operating mode of the synchronism check function must
be applied.
This concerns the following parameters:
203 Unom PRIMARY
204 Unom SECONDARY
210 U4 transformer
212 Usy2 connection
214 ϕ Usy2-Usy1
215 Usy1/Usy2 ratio
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
| within the permissible tolerance AR maxVolt.Diff or MC
– U
sy1 sy2
and f within the permitted operating range f
sy1 sy2
| lie within the permissible tolerance AR maxFreq.Diff or MC
– f
sy1 sy2
sy1
sy2
and f
sy1 sy2
primary rated voltage of the voltage transformers of the protective functions
(phase-to-phase) in kV, measuring point U
secondary rated voltage of the protective functions (phase-to-phase) in V,
measuring point U
Voltage measuring input U
voltage connection of measuring point U
phase displacement between the voltages U
switched in between;
ratio between the secondary voltage U
condition;
2.4 Synchronism and voltage check (optional)
N
and U .
sy1 sys2
sy1
;
sy1
must be set to Usy2 transf.;
4
(e.g. U
sy2
and voltage U
sy1
Functions
± 3 Hz?
;
),
L1–L2
and U if a transformer is
sy2 sy1
under nominal
sy2
87