ABB RELION REX640 - 9.5.5 Operation principle

For troubleshooting, check the contents of this chapter and also the preprocessing
blocks in this document. The configuration can be written to the protection relay
once the mismatch is corrected.
9.5.5 Operation principle
The function can be enabled and disabled with the
Operation setting. The
corresponding parameter values are "On" and "Off".
SECRSYN has two parallel functionalities, the synchro check and energizing check
functionality. The operation of SECRSYN can be described using a module diagram.
All the modules in the diagram are explained in the next sections.
SYNC_OK
BLOCK
Energizing
check
Synchro
check
CL_COMMAND
SYN_INPRO
CMD_FAIL_AL
CL_FAIL_AL
BYPASS
LLLB
LLDB
DLLB
DLDB
U3P1
U_A
U_B
U_C
U3P2
U_A_AB
Figure 843: Functional module diagram
If Energizing check is passed, no further conditions need to be fulfilled to permit
closing. Otherwise, Synchro check function can operate either with the U_AB or U_A
voltages. The selection of used voltages is defined with the VT connection setting
of the line voltage general parameters.
By default, voltages U_BUS and U_LINE are connected as presented in
Figure 852 . If necessary, connections can be switched by setting Voltage
source switch to “True”.
Energizing check
The Energizing check function checks the energizing direction. Energizing is defined
as a situation where a dead network part is connected to an energized section of
the network. The conditions of the network sections to be controlled by the circuit
breaker, that is, which side has to be live and which side dead, are determined by the
setting. A situation where both sides are dead is possible as well. The actual value
for defining the dead line or bus is given with the Dead bus value and Dead line
value settings. Similarly, the actual values of live line or bus are defined with the Live
bus value and Live line value settings.
1MRS759142 F
Control functions
REX640
Technical Manual
1545