ABB RELION 670 Series Technical Manual page 397

1MRK 502 066-UUS B
Measured mode
Z
posseq
Z
AB
Z
BC
Z
CA
There are three characteristics in LEXPDIS (40) protection as shown in figure 209.
Naimly:
• Offset mho circle for Z1
• Offset mho circle for Z2
• Directional blinder
Technical manual
Measured apparent impedance
V
posseq
=
I
posseq
(Equation 111)
EQUATION2051-ANSI V1 EN-US
-
V
V
=
A B
-
I
I
A B
(Equation 112)
EQUATION2052-ANSI V1 EN-US
-
V
V
=
B C
-
I
I
B C
(Equation 113)
EQUATION2053-ANSI V1 EN-US
-
V
V
=
C A
-
I
I
C A
(Equation 114)
EQUATION2054-ANSI V1 EN-US
Section 7
Impedance protection
391