ABB REL670 2.2 IEC - Page 436

2 2
400
160
1000
= = =
UBase
ZBase ohm
SBase
EQUATION1960 V1 EN-US (Equation 426)
2
400
( ) ( 2) 2 20 2 52
5000
ZA Z line Zsc station j j j ohm= + = + + = +
EQUATION1961 V1 EN-US (Equation 427)
This corresponds to:
2 52
0.0125 0.325 0.325 88
160
j
ZA j pu pu
+
= = + = Ð °
EQUATION1962 V1 EN-US (Equation 428)
Set ZA to 0.32.
2
400
( 1) 32
5000
ZB Zsc station j j ohm= = =
EQUATION1963 V1 EN-US (Equation 429)
This corresponds to:
32
0.20 0.20 90
160
j
ZB j pu pu= = = Ð °
EQUATION1964 V1 EN-US (Equation 430)
Set ZB to 0.2
This corresponds to:
2 20
0.0125 0.125 0.126 84
160
j
ZC j pu pu
+
= = + = Ð °
EQUATION1966 V1 EN-US (Equation 431)
Set ZC to 0.13 and AnglePhi to 88°
The warning angle (StartAngle) should be chosen not to cross into normal
operating area. The maximum line power is assumed to be 2000 MVA. This
corresponds to apparent impedance:
2 2
400
80
2000
U
Z ohm
S
= = =
EQUATION1967 V1 EN-US
(Equation 432)
Section 8 1MRK 506 369-UEN B
Impedance protection
430 Line distance protection REL670 2.2 IEC
Application manual