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I
AB
jX
V
AB
f
ArgDir
I
AB
ArgNegRes
ZPP
en07000111_ansi
ANSI07000111 V1 EN-US
Figure 101: Simplified offset mho characteristic in forward direction for phase A-to-B fault
Offset mho, reverse direction
SEMOD154224-265 v4
The operation area for offset mho in reverse direction is according to figure
area in second quadrant is
Ar180°.
Operation occurs if 90≤β≤270 and 180° -
ArgDir ≤φ ≤ Arg 180°
The β is derived according to equation for the mho circle and φ is the angle between the voltage
and current.
1MRK 502 066-UUS B
Section 7
Impedance protection
225
Technical manual
Summary of Contents for Relion 670 series
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