ABB Relion 670 Series Technical Reference Manual page 948

Section 15
Monitoring
942
The fault current is expressed in measurable quantities by:
I
F A
------- -
I =
F
D
A
EQUATION96 V1 EN
Where:
I is the change in current at the point of measurement, IED A and
FA
D is a fault current-distribution factor, that is, the ratio between the fault current at line end A and
A
the total fault current.
For a single line, the value is equal to:
( ) Z ×
1 p Z
– +
L B
-----------------------------------------
D =
A
Z + Z + Z
A L B
EQUATION97 V1 EN
Thus, the general fault location equation for a single line is:
I
= × × + ×
V I p Z FA R
A A L F
D
A
EQUATION1596 V1 EN
Table 579: Expressions for V
Fault type: V
A
AG V
BG V
CG V
ABC, AB, ABG V
BC, BCG V
CA, CAG V
The K complex quantity for zero-sequence compensation for the single line is equal to:
N
, I and I for different types of faults
A A FA
I
A
I + K
AA AA
I + K
BA BA
I + K
CA CA
-V I - I
AA BA AA
-V I - I
BA CA BA
-V I - I
CA AA CA
1MRK505222-UUS C
I
FA
x I
(
N NA 3
× D
2
EQUATION1597 V1 EN
x I
(
N NA
3
× D
2
EQUATION1598 V1 EN
x I
(
N NA
3 × D
2
EQUATION1599 V1 EN
DI
BA ABA
DI
CA CBA
DI
AA CAA
Technical reference manual
(Equation 182)
(Equation 183)
(Equation 184)
)
-
I I
AA 0 A
)
-
I I
BA 0 A
)
-
I I
CA 0 A