ABB RELION Series Technical Manual page 628

Section 9
Control functions
622
Closing
permission
SECRSYN
GUID-A9132EDC-BFAB-47CF-BB9D-FDE87EDE5FA5 V2 EN
Figure 317: 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.
Closing
request
CBXCBR
GUID-820585ED-8AED-45B1-8FC2-2CEE7727A65C V2 EN
Figure 318: A simplified block diagram of SECRSYN in the command mode
operation
The closing signal is delivered only once for each activated external closing command
signal. The pulse length of the delivered closing is set with the Close pulse setting.
Closing
command
CBXCBR
Closing
command
SECRSYN
1MRS758755 A
I
I
REC615 and RER615
Technical Manual