Example 2; Example 3 - ABB REB670 Applications Manual

1MRK 505 337-UUS -
4.2.2.1
4.2.2.2
Figure 16: Example how to set CT_WyePoint parameters in the IED
Application manual
Example 1
Two IEDs used for protection of two objects.
Transformer
I
p
Transformer
I
s
protection
IED
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
ANSI05000753 V2 EN
Figure 15: Example how to set CT_WyePoint parameters in the IED
The figure 15 shows the normal case where the objects have their own CTs. The settings
for CT direction shall be done according to the figure. To protect the line the direction of
the directional functions of the line protection shall be set to Forward. This means that the
protection is looking towards the line.

Example 2

Two IEDs used for protection of two objects and sharing a CT.
This example is similar to example 1, but here the transformer is feeding just one line and
the line protection uses the same CT as the transformer protection does. The CT direction
is set with different reference objects for the two IEDs though it is the same current from
the same CT that is feeding the two IEDs. With these settings the directional functions of
the line protection shall be set to Forward to look towards the line.
I
p
I
s
Setting of current input:
Set parameter
CT_WyePoint with
Transformer as
reference object.
Correct setting is
"ToObject"
Analog inputs
Line
I
p
Line
Reverse Forward
Definition of direction
for directional functions
Line protection
IED
Setting of current input:
Set parameter
CT_WyePoint with
Line as
reference object.
Correct setting is
"FromObject"
ANSI05000753.vsd
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