ABB 615 series Technical Manual page 813

1MAC059074-MB A
615 series ANSI
Technical Manual
These impedance values can be utilized as such or they can be further processed in system
level fault location applications, such as distribution management system (DMS).
Fault loops "AG Fault" or "BG Fault" or "CG Fault"
Fault loops "AG Fault", "BG Fault" or "CG Fault" are used for single-phase-to-ground
faults. When the individual ground faults are located at different feeders, they are also
applied in the case of two-phase-to-ground fault. In this case, the phase-to-ground loop
(either "AG Fault" or "BG Fault" or "CG Fault") corresponding to the faulty phase at the
protected feeder, is used for calculation.
model. The following impedances are measured and stored in the recorded data of 21FL.
Flt point resistance R
=
fault
GUID-2503378E-4AC5-4E9F-9D77-2E7C71592C37 V3 EN
Flt loop resistance R
= +
1
GUID-4DF67AFC-67E4-4BCB-958E-CC9E4872E252 V3 EN
Flt loop reactance X
= +
1
GUID-B4E21936-B993-4A8A-9C4A-7425F8AC4670 V3 EN
Flt phase reactance X
=
GUID-56EC16DD-7F6A-4DE5-935E-4302196DE21A V3 EN
R Estimated positive-sequence resistance from the substation to the fault location
1
X Estimated positive-sequence reactance from the substation to the fault location
1
R Estimated zero-sequence resistance from the substation to the fault location
0
X Estimated zero-sequence reactance from the substation to the fault location
0
R Estimated the ground return path resistance (= (R0 – R1)/3) from the substation to the
N
fault location
X Estimated is the ground return path reactance (= (X0 – X1)/3) from the substation to the
N
fault
R Estimated fault resistance at the fault location
fault
The recorded data Flt phase reactance provides the estimated positive-sequence reactance
from the substation to the fault location.
Figure 411
R R
+
N fault
X
N
1
Protection related functions
shows the phase-to-ground fault loop
Section 5
(Equation 138)
(Equation 139)
(Equation 140)
(Equation 141)
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