ABB REL650 Technical Manual page 106

Section 6
Impedance protection
100
UL1
Phase-to-earth
fault in phase L1
0
UL1
Phase-to-phase
fault in phase
L1-L2
UL2
UL1
Three-phase
fault or Phase-to-
phase-earth fault
UL3
IEC11000419 V3 EN-US
Figure 34: Fault loop model
Mho characteristic
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
offset mho.
R1Zx + j X1Zx
IL1
IN
(R0Zx-R1Zx)/3 +
j (X0Zx-X1Zx)/3 )
R1Zx + j X1Zx
IL1
IL2
R1Zx + j X1Zx
R1Zx + j X1Zx
IL1
IL3
R1Zx + j X1Zx
1MRK 506 382-UEN A
Phase-to-earth
element
RFPEZx
(Arc + tower
resistance)
Phase-to-phase
element L1-L2
RFPPZx
(Arc resistance)
0.5·RFPPZx
Phase-to-phase
element L1-L3
0.5·RFPPZx
IEC11000419-3-en.vsdx
GUID-9269239B-3A04-44CD-BE00-FD850D42836B v2
35 where zone 5 is selected
Line distance protection REL650 2.2 IEC
Technical manual