ABB REL670 2.2 IEC, Applications Manual

Page: 229 / 908

( )
( )
( )
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 119)
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
120 and
equation 121 .
Re( ) 0 (2 1 0 3 ) 0 ( 0 2 1) A R R R Rf X X X
= × × + + × - × + ×
EQUATION1285 V1 EN-US
(Equation 120)
0 1 0 1 0 1 0
Im( ) (2 3 ) (2 ) A X R R R R X X
= × × + + × + × × +
EQUATION1286 V1 EN-US
(Equation 121)
The real component of the KU factor is equal to equation 122 .
Re
Re
Re Im
K
A X
A A
u
m ( )
= +
( )
⋅
( )




+
( )




1
0
2
2 2
EQUATION1287 V3 EN-US
(Equation 122)
The imaginary component of the same factor is equal to equation 123 .
( )
( )
( ) ( )
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 123)
Ensure that the underreaching zones from both line ends will overlap a sufficient
amount (at least 10%) in the middle of the protected circuit.
8.3.2.7 Tapped line application
M17048-243 v3
1MRK 506 369-UEN B
Section 8
Impedance protection
Line distance protection REL670 2.2 IEC 223
Application manual