ABB REL670 2.2 IEC, Applications Manual

Page: 72 / 908

4.2.1 Setting of the phase reference channel
SEMOD55055-5 v3
All phase angles are calculated in relation to a defined reference. An appropriate
analog input channel is selected and used as phase reference. The parameter
PhaseAngleRef defines the analog channel that is used as phase angle reference.
4.2.1.1 Example
SEMOD55055-11 v5
Usually the L1 phase-to-earth voltage connected to the first VT channel number of
the transformer input module (TRM) is selected as the phase reference. The first
VT channel number depends on the type of transformer input module.
For a TRM with 6 current and 6 voltage inputs the first VT channel is 7. The
setting
PhaseAngleRef =7 shall be used if the phase reference voltage is connected
to that channel.
4.2.2 Setting of current channels
SEMOD55055-16 v6
The direction of a current to the IED is depending on the connection of the CT.
Unless indicated otherwise, the main CTs are supposed to be star connected and
can be connected with the earthing point to the object or from the object. This
information must be set in the IED. The convention of the directionality is defined
as follows: A positive value of current, power, and so on means that the quantity
has the direction into the object and a negative value means direction out from the
object. For directional functions the direction into the object is defined as Forward
and the direction out from the object is defined as Reverse. See Figure
6
A positive value of current, power, and so on (forward) means that the quantity
flows towards the object. A negative value of current, power, and so on (reverse)
means that the quantity flows away from the object. See Figure
6 .
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-US
Figure 6: Internal convention of the directionality in the IED
Section 4
1MRK 506 369-UEN B
Analog inputs
66 Line distance protection REL670 2.2 IEC
Application manual