Mho Characteristic - ABB REL650 series Technical Manual

Section 6
Impedance protection
6.1.6.4
108
X
IZKR
360°
180°
ANSI11000267 V1 EN
Figure 38: Blinder characteristic part of quadrilateral characteristic
When both the conditions are true then comparator is set as TRUE.
In phase to ground loop:
( )
= + × ×
IZKR I IN KN LineAng
GUID-C2FB458A-506E-419D-AD83-63209DE24BC4 V1 EN
Else, for phase to phase loop:
= ×
IZKR I LineAng
GUID-7C0E8F9F-2CF3-48BF-B0A9-F657B99F09FD V1 EN

Mho characteristic

ZQMPDIS (21) basically implements quadrilateral and mho characteristic in all the five
zones separately. Set CharPGZx or CharPPZx setting to Mho, to choose particular
measuring loop in a zone to work as mho distance protection.
Each distance protection zone can be selected to be either forward or reverse with positive
sequence polarized mho characteristic alternatively self polarized offset mho
characteristics with reverse offset. The operating characteristic is in accordance to
figure 39 where zone 5 is selected offset mho.
IZKR
IZKR
VAR
V
VBR
0°
I
I·RF
R
180°
1MRK 506 335-UUS A
ANSI11000267_1_en.vsd
(Equation 11)
(Equation 12)
Technical manual