ABB Relion 670 Series Applications Manual page 72

Section 4
Analog inputs
5)
6)
4.2.2.6 Example how to connect delta connected three-phase CT set to the IED
Figure 23
overview of the required actions by the user in order to make this measurement available to the built-in
protection and control functions in the IED as well.
A B
Protected Object
ANSI11000027 V3 EN-US
Figure 23: Delta DAB connected three-phase CT set
66
Is a connection made in the Signal Matrix tool (SMT) and Application configuration tool (ACT), which connects
the residual/neutral current input to the fourth input channel of the preprocessing function block 6). Note that
this connection in SMT shall not be done if the residual/neutral current is not connected to the IED.
Is a Preprocessing block that has the task to digitally filter the connected analog inputs and calculate:
• fundamental frequency phasors for all input channels
• harmonic content for all input channels
• positive, negative and zero sequence quantities by using the fundamental frequency phasors of the first
three input channels (channel one taken as reference for sequence quantities)
These calculated values are then available for all built-in protection and control functions within the IED, which
are connected to this preprocessing function block in the configuration tool. For this application, most of the
preprocessing settings can be left to the default values.
If frequency tracking and compensation is required (this feature is typically required only for IEDs installed in
the generating stations), then the setting parameters DFTReference shall be set accordingly.
gives an example how to connect a delta connected three-phase CT set to the IED. It gives an
For correct terminal designations, see the connection diagrams valid for the delivered
IED.
C
I_A-I_B
I_B-I_C
I_C-I_A
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IED
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1
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1MRK 505 370-UUS Rev. K
SEMOD55055-392 v7
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REVROT AI1
^GRP2_A AI2
^GRP2_B AI3
^GRP2_C AI4
^GRP2_N AIN
ANSI11000027-3-en.vsdx
Busbar protection REB670
Application manual