The fault current is expressed in measurable quantities by:
I
F
I
FA
D
A
--------
=
EQUATION96 V1 EN
(Equation 182)
Where:
I
FA
is the change in current at the point of measurement, IED A and
D
A
is a fault current-distribution factor, that is, the ratio between the fault current at line end A and
the total fault current.
For a single line, the value is equal to:
D
A
1 p
–
(
)
Z
×
L
Z
B
+
Z
A
Z
L
Z
B
+
+
-----------------------------------------
=
EQUATION97 V1 EN
(Equation 183)
Thus, the general fault location equation for a single line is:
FA
A
A
L
F
A
I
V
I p Z
R
D
= × ×
+
×
EQUATION1596 V1 EN
(Equation 184)
Table 579:
Expressions for V
A
, I
A
and I
FA
for different types of faults
Fault type:
V
A
I
A
I
FA
AG
V
AA
I
AA
+ K
N
x I
NA
(
)
AA
0 A
3
2
I
I
× D
-
EQUATION1597 V1 EN
BG
V
BA
I
BA
+ K
N
x I
NA
(
)
BA
0 A
3
2
I
I
× D
-
EQUATION1598 V1 EN
CG
V
CA
I
CA
+ K
N
x I
NA
(
)
CA
0 A
3
2
I
I
× D
-
EQUATION1599 V1 EN
ABC, AB, ABG
V
AA
-V
BA
I
AA
- I
BA
D
I
ABA
BC, BCG
V
BA
-V
CA
I
BA
- I
CA
D
I
CBA
CA, CAG
V
CA
-V
AA
I
CA
- I
AA
D
I
CAA
The K
N
complex quantity for zero-sequence compensation for the single line is equal to:
Section 15
1MRK505222-UUS C
Monitoring
942
Technical reference manual
Summary of Contents for Relion 670 series
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