ABB Relion 670 series - Page 948

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 0A
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
DI
ABA
BC, BCG V
BA
-V
CA
I
BA
- I
CA
DI
CBA
CA, CAG V
CA
-V
AA
I
CA
- I
AA
DI
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