ABB RELION REX640 Technical Manual page 1019

1MRS759142 F
Figure 565: Operating region of the impedance mho circle
It is possible to add a restraint with the help of settings
X and Rst offset X angle , as shown in the Figure
-R
Figure 566: Settings Restraint enable, Rst offset X and Rst offset X angle
REX640
Technical Manual
X (Reactance) p.u.
-R
Offset
Diameter Displacement
Operating Region
X (Reactance)
Rst offset X
R (Resistance) p.u.
-X
Figure 566
Underexcitation protection
Restrain area
Rst offset X angle
-X
Protection functions
Restraint enable , Rst offset
.
R (Resistance)
Directional
restraint
1019