Hitachi Relion 650 Series Technical Manual page 34

Section 3
Analog inputs
Definition of direction
for directional functions
Reverse
Set parameter
CTStarPoint
Correct Setting is
"ToObject"
D0E9312T201305151403 V1 EN-US
Figure 1:
If the settings of the primary CT is correct, that is CTStarPoint set as FromObject or ToObject
according to the plant condition, then a positive quantity always flows towards the protected object,
and a Forward direction always looks towards the protected object.
The settings of the IED are given in primary values. The ratios of the main CTs and VTs are therefore
basic data for the IED. The user has to set the rated secondary and primary currents and voltages of
the CTs and VTs to provide the IED with their rated ratios.
The CT and VT ratings are entered in SST, under the Reference signals milestone. Channel names
are assigned in the pre-configuration. Manual changes can be done under Main menu/Hardware /
Analog modules in the Parameter Settings tool or on the LHMI or WHMI.
28
Forward
Protected Object
Line, transformer, etc
e.g. P, Q, I
Measured quantity is
positive when flowing
towards the object
Internal convention of the directionality in the IED
© 2021 Hitachi Energy. All rights reserved.
1MRK 511 557-UEN Rev. A
Definition of direction
for directional functions
Forward Reverse
e.g. P, Q, I
Measured quantity is
positive when flowing
towards the object
Set parameter
CTStarPoint
Correct Setting is
"FromObject"
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Technical Manual