1200 1300 1400 1500 1600 1700 1800
-0.02
-0.01
0
0.01
0.02
0.03
G0 (blue) and G0 difference (red)
1300 1400 1500 1600 1700 1800
-0.01
-0.005
0
0.005
0.01
0.015
0.02
0.025
G0 (blue) and G0 difference (red)
Seling down delay
Seling down delay
Fault indicaon
Fault indicaon
Fault start transion
sele-down
Fault start transion
sele-down
Zero conductance gradient
rising edge
Zero conductance gradient
rising edge
TRIGG_T
t
1
t
1
t
2
t
2
Time delay
t
0
t
0
Figure 685: Fault distance estimate triggering moment definitions
Fault loops “AB Fault”, “BC Fault” or “CA Fault”
Fault loops “AB Fault”, “BC Fault” or “CA Fault” are used for phase-to-phase short
circuit faults as well as in the case of a two-phase-to-earth fault if the individual
earth faults are located at the same feeder.
Figure 686
shows the phase-to-phase
fault loop model. The following impedances are measured and stored in the
recorded data of SCEFRFLO.
Flt point resistance
R
fault
=
2
(Equation 299)
1MRS759142 F
Protection related functions
REX640
Technical Manual
1203