With all phase voltages and phase currents available and fed to the protection IED, it is
recommended to set the MeasureMode to positive sequence.
The impedance settings are set in pu with ZBase as reference:
2 2
400
160
1000
= = =
UBase
ZBase ohm
SBase
EQUATION1960 V1 EN-US (Equation 395)
2
400
( ) ( 2) 2 20 2 52
5000
ZA Z line Zsc station j j j ohm= + = + + = +
EQUATION1961 V1 EN-US (Equation 396)
This corresponds to:
2 52
0.0125 0.325 0.325 88
160
j
ZA j pu pu
+
= = + = Ð °
EQUATION1962 V1 EN-US (Equation 397)
Set ZA to 0.32.
2
400
( 1) 32
5000
ZB Zsc station j j ohm= = =
EQUATION1963 V1 EN-US (Equation 398)
This corresponds to:
32
0.20 0.20 90
160
j
ZB j pu pu= = = Ð °
EQUATION1964 V1 EN-US (Equation 399)
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 400)
Set ZC to 0.13 and AnglePhi to 88°
Section 8 1MRK 504 163-UUS A
Impedance protection
474 Transformer protection RET670 2.2 ANSI
Application manual
To Next Page
Loading...
