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2.13 Synchronism and Voltage Check
145
7ST6 Manual
E50417-G1176-C251-A3
• Is the magnitude of the voltage difference |ULine – URef| within the permissible limit
Max. Volt. Diff
?
• Are the two frequencies fRef and fLine within the permitted operating range f
N
±
3 Hz?
• Is the frequency difference |fLine – fRef| within the permissible limit
Max. Freq.
Diff
?
• Is the angle difference |
ϕ
Line –
ϕ
ref| within the permissible limit
Max. Angle
Diff
?
To check whether these conditions are observed for a certain minimum time, you can
set this minimum time as
T SYNC-STAB
. Checking the synchronism conditions can
also be confined to a maximum monitoring time
T-SYN. DURATION
. This implies that
the conditions must be fulfilled within the time
T-SYN. DURATION
for the duration of
T SYNC-STAB
. If this is the case, the closing release is released.
Switching under
Asynchronous
System Conditions
Before granting a release for closing under asynchronous conditions, the following
conditions are checked:
• Is the reference voltage URef above the setting value
Live Volt. Thr.
but
below the maximum voltage
Umax
?
• Is the feeder voltage ULine above the setting value
Live Volt. Thr.
but below
the maximum voltage
Umax
?
• Is the magnitude of the voltage difference |ULine – URef| within the permissible limit
Max. Volt. Diff
?
• Are the two frequencies fRef and fLine within the permitted operating range f
±
3 Hz?
• Is the frequency difference |fLine – fRef| within the permissible limit
Max. Freq.
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.
2.13.2 Setting Notes
Preconditions
When setting the general power system data (refer to section 2.1.3.1) a number of pa-
rameters regarding the measured quantities and the operating mode of the synchro-
nism check function must be applied.
This concerns the following parameters:
204
Unom PRIMARY
Primary rated voltage of the voltage transformers in kV;
205
Unom SECONDARY
Secondary rated voltage of the voltage transformers in V;
215
Uline/Uref
Matching factor for different transformers of overhead
contact line voltage ULine and reference voltage URef;
230
Rated Frequency
The operating range of the synchronism check refers
to the nominal frequency of the power system
(f
N
±
3 Hz);
and, if closing at asynchronous system conditions is allowed,
239
T-CB close
the closing time of the circuit breaker.
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Содержание SIPROTEC 7ST6
Страница 14: ...Contents 14 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 24: ...1 Introduction 24 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 254: ...3 Mounting and Commissioning 254 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 288: ...4 Technical Data 288 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 340: ...A Appendix 340 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 342: ...Literature 342 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 354: ...Index 354 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 355: ...Index 355 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 356: ...Index 356 7ST6 Manual E50417 G1176 C251 A3 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...