ABB REC670 Applications Manual page 406

Section 14
Control
400
HV-side
Pforward
Qforward
(inductive)
LV-side
IEC06000536 V2 EN-US
Figure 178: Power direction references
With the four outputs in the function block available, it is possible to do more than
just supervise a level of power flow in one direction. By combining the outputs
with logical elements in application configuration, it is also possible to cover for
example, intervals as well as areas in the P-Q plane.
Busbar topology logic
Information of the busbar topology that is, position of circuit breakers and
isolators, yielding which transformers that are connected to which busbar and
which busbars that are connected to each other, is vital for the Automatic voltage
control for tap changer, parallel control function TR8ATCC when the circulating
current or the master-follower method is used. This information tells each
TR8ATCC, which transformers that it has to consider in the parallel control.
In a simple case, when only the switchgear in the transformer bays needs to be
considered, there is a built-in function in TR8ATCC block that can provide
information on whether a transformer is connected to the parallel group or not. This
is made by connecting the transformer CB auxiliary contact status to TR8ATCC
function block input DISC, which can be made via a binary input, or via GOOSE
from another IED in the substation. When the transformer CB is open, this
activates that input which in turn will make a corresponding signal DISC=1 in
TR8ATCC data set. This data set is the same data package as the package that
contains all TR8ATCC data transmitted to the other transformers in the parallel
group (see section "Exchange of information between TR8ATCC functions"
more details). Figure 179
lead to T3 sending the DISC=1 signal to the other two parallel TR8ATCC modules
(T1 and T2) in the group. Also see table 39.
IED
ATCC
IEC06000536_1_en.vsd
shows an example where T3 is disconnected which will
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Application manual