ABB Relion 650 Series Technical Manual page 482

Section 13
Monitoring
=
V I p Z
A A
EQUATION1595 V1 EN-US
Where:
I
A
I
F
p
The fault current is expressed in measurable quantities by:
I
F A
------- -
I =
F
D
A
EQUATION96 V1 EN-US
Where:
I
FA
D
A
For a single line, the value is equal to:
(
1 p
D -----------------------------------------
=
A
Z
EQUATION97 V1 EN-US
Thus, the general fault location equation for a single line is:
=
V I p Z
A A
EQUATION1596 V1 EN-US
476
× × + ×
I R
L F F
is the line current after the fault, that is, pre-fault current plus current change due to the fault,
is the fault current and
is a relative distance to the fault
is the change in current at the point of measurement, IED A and
is a fault current-distribution factor, that is, the ratio between the fault current at line end A and the total
fault current.
) Z ×
– + Z
L B
Z Z
+ +
A L B
I
× × + ×
FA R
L F
D
A
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1MRK 506 326-UUS B
(Equation 83)
(Equation 84)
(Equation 85)
(Equation 86)
Line distance protection REL650
Technical manual