Closing under asynchronous system conditions
Before releasing a closing command under 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
sy1
– U
sy2
|within the permissible tolerance
AR maxVolt.Diff
or
MC
maxVolt.Diff
?
•
Are the two frequencies f
sy1
and f
sy2
within the permitted operating range f
N
± 3 Hz?
•
Is the frequency difference |f
sy1
– f
sy2
| within the permissible tolerance
AR maxFreq.Diff
or
MC
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
sy1
•
Value of the voltage to be synchronized U
sy2
•
Frequency values f
sy1
and f
sy2
•
Differences of voltage, frequency and angle between U
sy1
and U
sys2
.
The primary measured values of the synchronism check are summarized in one of the preset default displays
(see Appendix
D Default Settings and Protocol-dependent Functions
).
Setting Notes
Preconditions
When setting the general power system data a number of parameters regarding the measured quantities and
the operating mode of the synchronism check function must be applied.
This concerns the following parameters:
203
Unom PRIMARY
primary rated voltage of the voltage transformers of
the protection functions (phase-to-phase) in kV,
measuring point U
sy1
;
204
Unom SECONDARY
secondary rated voltage of the protection functions
(phase-to-phase) in V, measuring point U
sy1
;
210
U4 transformer
voltage measurement input U
4
must be set to
Usy2
transf.
;
212
Usy2 connection
voltage connection of measuring point U
sy2
(e.g. U
L1–
L2
),
214
φ Usy2-Usy1
phase displacement between the voltages U
sy2
and
U
sy1
if a transformer is switched in between;
215
Usy1/Usy2 ratio
ratio between the secondary voltage U
sy1
and voltage
U
sy2
under nominal condition;
2.4.2
Functions
2.4 Synchronism and voltage check (optional)
SIPROTEC 4, 7VK61, Manual
89
C53000-G1176-C159-5, Edition 05.2018
Summary of Contents for SIPROTEC 4 7VK61
Page 8: ...8 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 10: ...10 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 16: ...16 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 176: ...176 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 224: ...224 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 264: ...264 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 270: ...270 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 276: ...276 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...
Page 346: ...346 SIPROTEC 4 7VK61 Manual C53000 G1176 C159 5 Edition 05 2018 ...