ABB ret650, Applications Manual

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T1
T2 T3
99000952.VSD
U
1
U
2
U
3
Z
1
Z
2
Z
3
I
1
I
2
I
3
=0
I
L
=I
1
+I
2
IEC99000952 V1 EN-US
Figure 80: Disconnection of one transformer in a parallel group
When the busbar arrangement is more complicated with more buses and bus
couplers/bus sections, it is necessary to engineer a specific station topology logic.
This logic can be built in the application configuration in PCM600 and will keep
record on which transformers that are in parallel (in one or more parallel groups).
In each TR8ATCC function block there are eight binary inputs (T1INCLD,...,
T8INCLD) that will be activated from the logic depending on which transformers
that are in parallel with the transformer to whom the TR8ATCC function block
belongs.
TR8ATCC function block is also fitted with eight outputs (T1PG,..., T8PG) for
indication of the actual composition of the parallel group that it itself is part of. If
parallel operation mode has been selected in the IED with setting
TrfId = Tx , then
the TxPG signal will always be set to 1. The parallel function will consider
communication messages only from the voltage control functions working in
parallel (according to the current station configuration). When the parallel voltage
control function detects that no other transformers work in parallel it will behave as
a single voltage control function in automatic mode.
Exchange of information between TR8ATCC functions
SEMOD159053-267 v6
Each transformer in a parallel group needs an Automatic voltage control for tap
changer, parallel control TR8ATCC function block of its own for the parallel
voltage control. Communication between these TR8ATCCs is made either on the
GOOSE interbay communication on the IEC 61850 protocol if TR8ATCC
functions reside in different IEDs, or alternatively configured internally in one IED
if multiple instances of TR8ATCC reside in the same IED. Complete exchange of
TR8ATCC data, analog as well as binary, on GOOSE is made cyclically every 300
ms.
TR8ATCC function block has an output ATCCOUT. This output contains two sets
of signals. One is the data set that needs to be transmitted to other TR8ATCC
blocks in the same parallel group, and the other is the data set that is transferred to
the TCMYLTC or TCLYLTC function block for the same transformer as
TR8ATCC block belongs to.
Section 11
1MRK 504 169-UEN A
Control
212 Transformer protection RET650 2.2 IEC
Application manual