ABB 615 Series - Page 987

25 52
I
Closing
permission
Closing
command
GUID-3921CB7B-0BBD-4BB3-B0E7-BFF043900C97 V1 EN
Figure 494: A simplified block diagram of the Synchro check function in the
continuous mode operation
Command mode
If Control mode is set to "Command", the purpose of the Synchro check functionality in
the command mode is to find the instant when the voltages on both sides of the circuit
breaker are in synchronism. The conditions for synchronism are met when the voltages on
both sides of the circuit breaker have the same frequency and are in phase with a
magnitude that makes the concerned busbars or lines such that they can be regarded as
live.
In the command mode operation, an external command signal CL_COMMAND, besides the
normal closing conditions, is needed for delivering the closing signal. In the command
control mode operation, the Synchro check function itself closes the breaker via the
SYNC_OK output when the conditions are fulfilled. In this case, the control function block
delivers the command signal to close the Synchro check function for the releasing of a
closing-signal pulse to the circuit breaker. If the closing conditions are fulfilled during a
permitted check time set with Maximum Syn time, the Synchro check function delivers a
closing signal to the circuit breaker after the command signal is delivered for closing.
2552
I
Closing
request
Closing
command
GUID-2AF445C8-388A-42DF-B5B3-070C34F3C7AB V2 EN
Figure 495: A simplified block diagram of 25 in the command mode operation
1MAC059074-MB A Section 9
Control functions
615 series ANSI 981
Technical Manual