( )
( )
( )
( )
2
0
2
2
Im
Im
Re
Im
m
U
A X
K
A
A
×
=
+
é
ù
é
ù
ë
û
ë
û
EQUATION1288 V2 EN-US
(Equation 49)
Ensure that the underreaching zones from both line ends will overlap a sufficient
amount (at least 10%) in the middle of the protected circuit.
8.1.2.7
Tapped line application
SEMOD168232-266 v2
SEMOD168232-268 v2
C
A
B
BC
ANSI05000224-2-en.vsd
ANSI05000224 V2 EN-US
Figure 78:
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 is as follows:
1MRK 504 163-UUS A
Section 8
Impedance protection
Transformer protection RET670 2.2 ANSI
203
Application manual
Summary of Contents for RELION RET670
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