ABB RELION REX640 - Page 1019

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