ABB REL670 2.2 IEC - Tapped Line Application

0 1 0 1 0 1 0
Im( ) (2 3 ) (2 )A X R R R R X X= × × + + × + × × +
EQUATION1286 V1 EN-US (Equation 306)
The real component of the KU factor is equal to equation 307.
Re
Re
Re Im
K
A X
A A
u
m
( )
= +
( )
⋅
( )




+
( )




1
0
2
2 2
EQUATION1287 V3 EN-US (Equation 307)
The imaginary component of the same factor is equal to equation 308.
( )
( )
( ) ( )
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 308)
Ensure that the underreaching zones from both line ends will overlap a sufficient
amount (at least 10%) in the middle of the protected circuit.
8.12.2.7 Tapped line application
GUID-740E8C46-45EE-4CE8-8718-9FAE658E9FCE v1
GUID-7AA566A4-B6E9-41A7-9927-4DAB50BE8D1A v1
C
B
BC
IEC09000160-3-en.vsd
A
IEC09000160 V3 EN-US
Figure 179: Example of tapped line with Auto transformer
1MRK 506 369-UEN B Section 8
Impedance protection
Line distance protection REL670 2.2 IEC 345
Application manual