ABB RELION 670 Series Technical Manual page 400

Section 7
Impedance protection
XoffsetDirLine
IEC06000457 V1 EN-US
Figure 211: Impedance constructed as XoffsetDirLine in LEXPDIS (40) protection
LEXPDIS (40) function is schematically described in figure 212.
Positive
sequence
current
phasor
Positive
Apparent
sequence
impedance
voltage
calculation
phasor
Dir.Restrain Enabled
ANSI06000458 V2 EN-US
Figure 212: Simplified logic diagram of LEXPDIS (40) protection
394
X
Underexcitation Protection
Restrain area
DirAngle
Z in
Z1 char.
Z
Z in
Z2 char.
Dir.
Restrain
R
Z (apparent impedance)
en06000457.vsd
AND
AND
OR
1MRK 502 066-UUS B
pickupZ1
tZ1 TripZ1
0
pickupZ2
TripZ2
tZ2
0
en06000458-
2_ansi.vsd
Technical manual