ABB REL670 2.2 IEC, Applications Manual

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( )
( )
( )
2
1 0
0
1 0
0
1 0
1
2
3
1
1
2 3
2
3
E f
m
U
f
f
Z Z R
Z
K
Z Z Z R
Z Z R
× × + +
= = -
× × + +
× × + +
EQUATION1284 V1 EN-US
(Equation 350)
This means that the reach is reduced in reactive and resistive directions. If the real
and imaginary components of the constant A are equal to equation
351 and
equation 352 .
Re( ) 0 (2 1 0 3 ) 0 ( 0 2 1) A R R R Rf X X X
= × × + + × - × + ×
EQUATION1285 V1 EN-US
(Equation 351)
0 1 0 1 0 1 0
Im( ) (2 3 ) (2 ) A X R R R R X X
= × × + + × + × × +
EQUATION1286 V1 EN-US
(Equation 352)
The real component of the KU factor is equal to equation 353 .
Re
Re
Re Im
K
A X
A A
u
m
( )
= +
( )
⋅
( )




+
( )




1
0
2
2 2
EQUATION1287 V3 EN-US
(Equation 353)
The imaginary component of the same factor is equal to equation 354 .
( )
( )
( ) ( )
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 354)
Ensure that the underreaching zones from both line ends will overlap a sufficient
amount (at least 10%) in the middle of the protected circuit.
8.13.2.7 Tapped line application
GUID-4DFD6015-E97C-4F7E-84CA-C7CD2438C55A v1
1MRK 506 369-UEN B
Section 8
Impedance protection
Line distance protection REL670 2.2 IEC 371
Application manual