ABB RELION REX640 - Page 1290

-U
0
( polarizing quantity)
Max forward
angle
Min forward
angle
Min reverse
angle
Non-operating area
Forward
area
I
0
( operating quantity)
Max reverse
angle
Backward
area
Non-operating area
Characteristic angle/
Max torque line
Min operate voltage
Min operate current
RCA = 0 deg
Zero torque line
Figure 731: Configurable directional setting for Zero seq. volt. (residual voltage)
using the Pol quantity setting
The Characteristic angle setting is done based on method of grounding employed
in the network. For example, in case of an isolated network, Characteristic angle
is set to –90°, and in case of a compensated network, Characteristic angle is
set to 0° and 60° for solidly grounded systems. In general Characteristic angle is
selected so that it matches close to the expected fault angle value, which results
in maximum sensitivity. Characteristic angle can be set anywhere between –179° to
+180°. The figures show examples of the operating area with RCA set to +60° and
–90°, respectively.
-U
0
( polarizing quantity)
I
0
(operating quantity)
RCA=+60 deg
Min forward
angle
Max forward
angle
Min reverse
angle
Max reverse
angle
Backward
area
Forward
area
Min Operate voltage
Min operate current
Characteristic
Angle/ Max torque
line
Zero torque line
Figure 732: Configurable directional characteristics (RCA =+60˚) for a solidly
earthed network
Protection related functions
1MRS759142 F
1290 REX640
Technical Manual