![background image](http://html1.mh-extra.com/html/abb/relion-670-series/relion-670-series_applications-manual_3052129283.webp)
sequence impedance circuit for faults at the remote bus bar can be simplified to the circuit
shown in figure
The line zero sequence mutual impedance does not influence the measurement of the distance
protection in a faulty circuit.
A
B
C
IEC09000255_1_en.vsd
I
0
I
0
Z
0m
Z
0
-
Z
0m
Z
0m
Z
0
-
IEC09000255 V1 EN-US
Figure 171: Equivalent zero sequence impedance circuit for a double-circuit line with one
circuit disconnected and not earthed.
7.9.2.7
Tapped line application
GUID-1230B60C-8C3C-4405-8209-E089CAF07847 v1
C
B
BC
IEC09000160-3-en.vsd
A
IEC09000160 V3 EN-US
Figure 172: Example of tapped line with Auto transformer.
This application gives rise to similar problem that was highlighted in section
, that is increased measured impedance due to fault current infeed. For
example, for faults between the T point and B station the measured impedance at A and C will
be
Z
A
=Z
AT
+ ·Z
TF
I
A
+ I
C
I
A
DOCUMENT11524-IMG3509 V3 EN-US
(Equation 269)
1MRK 505 343-UEN B
Section 7
Impedance protection
277
Application manual
Содержание Relion 670 series
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