ABB Relion 670 series - Page 397

Measured mode Measured apparent impedance
Z
posseq
posseq
posseq
V
I
=
EQUATION2051-ANSI V1 EN-US (Equation 111)
Z
AB
A B
A B
V
I
V
I
=
-
-
EQUATION2052-ANSI V1 EN-US (Equation 112)
Z
BC
B C
B C
V
I
V
I
=
-
-
EQUATION2053-ANSI V1 EN-US (Equation 113)
Z
CA
C A
C A
V
I
V
I
=
-
-
EQUATION2054-ANSI V1 EN-US (Equation 114)
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
1MRK 502 066-UUS B Section 7
Impedance protection
391
Technical manual