Example How To Connect Delta Connected Three-Phase Ct Set To The Ied - ABB RET650 Applications Manual

Section 4
Analog inputs
4.2.2.6
48
5) 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.
6) 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.
Example how to connect delta connected three-phase CT set to the
IED
Figure 14 gives an example how to connect a delta connected three-phase CT set to
the IED. It gives an 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.
For correct terminal designations, see the connection diagrams
valid for the delivered IED.
1MRK 504 169-UEN A
SEMOD55055-392 v7
Transformer protection RET650 2.2 IEC
Application manual