Synchrocheck; Synchronous / Asynchronous (Only 7Sj64) - Siemens SIPROTEC 7SJ62 Manual

2.19.1.2 Synchrocheck

Having selected operating mode SYNCHROCHECK the mode verifies the synchronism before connecting the two
system components and cancels the connecting process if parameters for synchronism lie outside the config-
ured thresholds.
Before a release is granted, the following conditions are checked:
• Is the reference voltage V
• Is the voltage V
• Is the voltage difference V
• Is the voltage difference V
• Are the two frequencies f
• Is the frequency difference f
• Is the frequency difference f
• Is the angle difference α
• Is the angle difference α

2.19.1.3 Synchronous / Asynchronous (only 7SJ64)

The operating mode ASYN/SYNCHRON uses the frequency slip of the two power systems (parameter F
SYNCHRON) to determine whether the power systems are asynchronous to each other ("Switching under Asyn-
chronous System Conditions") or synchronous ("Switching under Synchronous System Conditions"). The syn-
chronous condition is indicated by the message „Sync f syn" (170.2332). If the systems are asynchronous,
the time window for switching is passed relatively quickly. Therefore, it is sensible to take the operating time of
the circuit breaker into account. Thus the device can issue the ON command at a time where asynchronous
conditions are still prevailing. As soon as the poles make contact the conditions will be synchronous.
It is also possible to generally take into account the operating time of the circuit breaker, i.e. also with synchro-
nous conditions prevailing.
Switching under Synchronous System Conditions
Switching under synchronous conditions means that the ON command will be released as soon as the charac-
teristic data (voltage difference, angle difference) are within the thresholds specified by configuration.
Before granting a release for closing under synchronous conditions, the following conditions are checked:
• Is the reference voltage V
• Is the voltage V
• Is the voltage difference V
• Is the voltage difference V
• Are the two frequencies f
• Is the frequency difference smaller than the configured threshold frequency difference F SYNCHRON which
defines the transition from synchronous to asynchronous systems?
• Is the angle difference α
• Is the angle difference α
As soon as all synchronism conditions are fulfilled, the message „25 Synchron" is issued.
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
above the setting value Vmin but below the maximum voltage Vmax?
1
to be synchronized above the setting value Vmin but below the maximum voltage Vmax?
2
within the permitted threshold dV SYNCHK V2>V1?
– V
2 1
within the permitted threshold dV SYNCHK V2<V1?
– V
1 2
and f within the permitted operating range f
1 2
within the permitted threshold df SYNCHK f2>f1?
– f
2 1
within the permitted threshold df SYNCHK f2<f1?
– f
1 2
– α within the permitted threshold dα SYNCHK α2>α1?
2 1
– α within the permitted threshold dα SYNCHK α2<α1?
1 2
above the setting value Vmin but below the maximum voltage Vmax?
1
to be synchronized above the setting value Vmin but below the maximum voltage Vmax?
2
within the permitted threshold dV SYNC V2>V1?
– V
2 1
within the permitted threshold dV SYNC V2<V1?
– V
1 2
and f within the permitted operating range f
1 2
– α within the permitted threshold dα SYNC α2> α1?
2 1
– α within the permitted threshold dα SYNC α2< α1?
1 2
2.19 Synchronization Function
± 3 Hz?
Nom
± 3 Hz?
Nom
Functions
309