ABB Relion REQ650, Руководство по применению

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A positive value of current, power, and so on (forward) means that the quantity has a
direction towards the object. - A negative value of current, power, and so on (reverse)
means a direction away from the object. See figure
22 .
Protected Object
Line, transformer, etc
Forward Reverse
Definition of direction
for directional functions
Measured quantity is
positive when flowing
towards the object
e.g. P, Q, I
Reverse Forward
Definition of direction
for directional functions
e.g. P, Q, I
Measured quantity is
positive when flowing
towards the object
Set parameter
CTStarPoint
Correct Setting is
"ToObject"
Set parameter
CTStarPoint
Correct Setting is
"FromObject"
en05000456.vsd
IEC05000456 V1 EN
Figure 22: Internal convention of the directionality in the IED
With correct setting of the primary CT direction, CTStarPoint set to FromObject or
ToObject , a positive quantity always flows towards the protected object and a
direction defined as Forward is always looking towards the protected object. The
following examples show the principle.
4.2.3.1 Example 1
Two IEDs used for protection of two objects.
1MRK 505 291-UEN A
Section 4
Analog inputs
63
Application manual