ABB RER670 - Example 1; Example 2

With correct setting of the primary CT direction, CTStarPoint set to FromObject
or
ToObject, a positive quantities always flowing towards the protected object and a
direction defined as Forward always is looking towards the protected object. The
following examples show the principle.
4.2.2.1 Example 1
SEMOD55055-23 v6
Two IEDs used for protection of two objects.
Transformer
protection
Transformer
Line
Line
Setting of current input:
Set parameter
CTStarPoint with
Transformer as
reference object.
Correct setting is
"ToObject"
ForwardReverse
Definition of direction
for directional functions
Line protection
Setting of current input:
Set parameter
CTStarPoint with
Transformer as
reference object.
Correct setting is
"ToObject"
Setting of current input:
Set parameter
CTStarPoint with
Line as
reference object.
Correct setting is
"FromObject"
IEC05000753=IEC05
000753=1=en=Origin
al[1].vsd
I
s
I
s
I
p
I
p
I
p
IED
IED
IEC05000753 V2 EN-US
Figure 7: Example how to set CTStarPoint parameters in the IED
Figure
7 shows the normal case where the objects have their own CTs. The settings
for CT direction shall be done according to the figure. T
o protect the line, direction
of the directional functions of the line protection shall be set to Forward. This
means that the protection is looking towards the line.
4.2.2.2 Example 2
SEMOD55055-29 v7
Two IEDs used for protection of two objects and sharing a CT.
1MRK 506 375-UEN A Section 4
Analog inputs
Railway application RER670 2.2 IEC 45
Application manual