Operation Principle - ABB RELION Series Technical Manual

Section 9
Control functions
9.3.4
618
Asynchronous operation mode is provided for asynchronously running systems. The
main purpose of the asynchronous operation mode is to provide a controlled closing
of circuit breakers when two asynchronous systems are connected.
The synchrocheck operation mode checks that the voltages on both sides of the circuit
breaker are perfectly synchronized. It is used to perform a controlled reconnection of
two systems which are divided after islanding and it is also used to perform a
controlled reconnection of the system after reclosing.
The energizing check function checks that at least one side is dead to ensure that
closing can be done safely.
The function contains a blocking functionality. It is possible to block function outputs
and timers if desired.

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.
GUID-FE07029C-C6C1-4BA7-9F8E-CACE86D0A9BD V2 EN
Figure 315: 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
Voltage source switch to "True".
Energizing
check
Synchro
check
324. If necessary, connections can be switched by setting
1MRS758755 A
REC615 and RER615
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