Operation Principle - ABB RELION REX640 Technical Manual

Section 9
Control functions
9.8.4
1450
ASCGAPC performs the network topology determination to identify the subnetworks
within the whole network. It routes the voltage and frequency difference values from
the synchronizing CB to all the generator sources. It also identifies the sources which
are eligible to participate in matching the voltage and frequency difference.
ASCGAPC allows to select sources for synchronization and gives permission for
matching to the selected sources after essential checks.
ASCGAPC allows autosynchronization of only one non-source circuit breaker at a
time. It also provides the voltage and frequency matching status for the
synchronization in progress.

Operation principle

The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "on" and "off".
The operation of ASCGAPC can be described with a module diagram. All the
modules in the diagram are explained in the next sections.
SRC1_ASC_DAT
. .
. .
SRC8_ASC_DAT
NS1_ASC_DAT
. .
. .
NS17_ASC_DAT
U_DIFF_1
. .
. .
U_DIFF_17
FR_DIFF_1
. .
. .
FR_DIFF_17
BLOCK
GUID-253FAE09-74CD-4826-92A1-E7757CE3215C V1 EN
Figure 779: Functional module diagram
Topology determination
This module identifies the group of busbars, power sources and network circuit
breakers electrically connected together and calculates the subnetwork number for
each group. It also identifies the sources and buses which are electrically connected to
the external network. The maximum network configuration considered is 8 sources, 8
source CBs (SCB), 15 busbars and 17 non-source CBs (NSCB).
The equipment which is capable of voltage and frequency adjustment,
that is, the generator, is referred to as source and the rest as non-
source. Hence the generator CB is referred to as source CB and the bus
Topology
determinat-
ion
AS_CONFLICT
U_DIFF
FR_DIFF
ASC_NS1_DAT
ASC_NS2_DAT
Coordinator
ASC_NS2_DAT
ASC_SRC1_DAT
. .
.
ASC_SRC8_DAT
1MRS759142 C
REX640
Technical Manual