ABB RET670 - Page 682

• SetV
• VCTRStatus
• X2
The transformers controlled in parallel with the circulating current method or the master-
follower method must be assigned unique identities. These identities are entered as a
setting in each TR8ATCC (90), and they are predefined as T1, T2, T3,..., T8
(transformers 1 to 8). In figure 286 there are three transformers with the parameter
TrfId set to T1, T2 and T3, respectively.
For parallel control with the circulating current method or the master-follower method
alternatively, the same type of data set as described above, must be exchanged between
two TR8ATCC (90). To achieve this, each TR8ATCC (90) is transmitting its own data
set on the output ATCCOUT as previously mentioned. To receive data from the other
transformers in the parallel group, the output ATCCOUT from each transformer must
be connected (via GOOSE or internally in the application configuration) to the inputs
HORIZx (x = identifier for the other transformers in the parallel group) on TR8ATCC
(90) function block. Apart from this, there is also a setting in each TR8ATCC =/,..., =/
T1RXOP=Off/On,..., T8RXOP=Off/ On. This setting determines from which of the
other transformer individuals that data shall be received. Settings in the three
TR8ATCC blocks for the transformers in figure
286, would then be according to the
table
160:
Table 160: Setting of TxRXOP
TrfId=T1
T1RXOP=O
ff
T2RXOP=O
n
T3RXOP=O
n
T4RXOP=O
ff
T5RXOP=O
ff
T6RXOP=O
ff
T7RXOP=O
ff
T8RXOP=Off
TrfId=T2 T1RXOP=O
n
T2RXOP=O
ff
T3RXOP=O
n
T4RXOP=O
ff
T5RXOP=O
ff
T6RXOP=O
ff
T7RXOP=O
ff
T8RXOP=Off
TrfId=T3 T1RXOP=O
n
T2RXOP=O
n
T3RXOP=O
ff
T4RXOP=O
ff
T5RXOP=O
ff
T6RXOP=O
ff
T7RXOP=O
ff
T8RXOP=Off
Observe that this parameter must be set to Disabled for the “own” transformer. (for
transformer with identity T1 parameter T1RXOP must be set to Disabled, and so on.
Blocking
Blocking conditions
The purpose of blocking is to prevent the tap changer from operating under conditions
that can damage it, or otherwise when the conditions are such that power system
related limits would be exceeded or when, for example the conditions for automatic
control are not met.
For the Automatic voltage control for tap changer function, TR1ATCC (90) for single
control and TR8ATCC (90) for parallel control, three types of blocking are used:
Section 3 1MRK504116-UUS C
IED application
676
Application manual