VA
R1 + j X1
IA
RFPG
Phase-to-ground
fault in phase A
Phase-to-phase
fault in phase
A-B
Three-phase
fault or Phase-to-
phase-ground fault
(Arc + tower
resistance)
N
(R0-R1)/3 +
j (X0-X1)/3 )
IG
VA
R1 + j X1
IA
VB
R1 + j X1
IB
RFPP
VA
R1 + j X1
IA
VC
R1 + j X1
IC
0.5·RFPP
0.5·RFPP
(Arc resistance)
Phase-to-ground
element
Phase-to-phase
element A-B
Phase-to-phase
element A-C
ANSI11000419-3-en.vsd
ANSI11000419 V3 EN-US
Figure 152: Fault loop model
Mho characteristic
GUID-9269239B-3A04-44CD-BE00-FD850D42836B v2
ZMFPDIS implements quadrilateral and mho characteristic in all the six zones separately. Set
OpModePEZx
or
OpModePPZx
setting to
Mho
or
Offset
, to choose a particular measuring loop in a
zone to work as mho (or Offset Mho) distance protection.
Zones 3 to 5 can be selected to be either forward or reverse with positive sequence polarized mho
characteristic; alternatively self polarized offset mho characteristics. The operating characteristic
is in accordance to figure
153 where zone 5 is selected offset mho.
Section 7 1MRK 502 066-UUS B
Impedance protection
308
Technical manual
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