ABB Relion 650 Series Technical Manual page 481

1MRK 506 326-UUS B
algorithm described below. It's also possible to change fault loop. In this way, a more accurate
location of the fault can be achieved.
The function indicates the distance to the fault as a percentage of the line length. The fault
location is stored as a part of the disturbance report information and managed via the LHMI or
PCM600.
13.13.7.1 Measuring Principle
For transmission lines with voltage sources at both line ends, the effect of double-end infeed and
additional fault resistance must be considered when calculating the distance to the fault from the
currents and voltages at one line end. If this is not done, the accuracy of the calculated figure will
vary with the load flow and the amount of additional fault resistance.
The calculation algorithm used in the fault locator in compensates for the effect of double-end
infeed, additional fault resistance and load current.
13.13.7.2 Accurate algorithm for measurement of distance to fault
Figure 247
with source impedances Z
line with the length L and impedance Z
used for better clarification of the algorithm.
Z
A
ANSI01000171 V1 EN-US
Figure 247: Fault on transmission line fed from both ends
From figure
Line distance protection REL650
Technical manual
shows a single-line diagram of a single transmission line, that is fed from both ends
and Z . Assume that the fault occurs at a distance F from IED A on a
A B
L
F
A
pZ
I I
L
A B
I
F
V
R
F
A
247 it is evident that:
© Copyright 2011 ABB Power Grids. All rights reserved
. The fault resistance is defined as R
L
B
(1-p).Z Z
L B
xx01000171_ansi.vsd
Section 13
Monitoring
M14983-4 v2
M14983-7 v4
. A single-line model is
F
475