ABB Relion REG670, Applications Manual

Page: 279 / 780

Short circuit power from the external network without infeed from the protected line:
5000 MVA (assumed to a pure reactance).
We have all phase voltages and phase currents available and fed to the protection IED.
Therefore it is recommended to set the
MeasureMode to positive sequence.
The impedance settings are set in pu with ZBase as reference:
2 2
20
2.0
200
UBase
ZBase ohm
SBase
= = =
EQUATION1969 V1 EN
(Equation 159)
2 2
20 20
( ) ( ) 0.15 0.38
200 5000
ZA Z transf Zsc network j j j ohm
= + = × + =
EQUATION1970 V1 EN
(Equation 160)
This corresponds to:
0.38
0.19 0.19 90
2.0
j
ZA j pu pu
= = = Ð °
EQUATION1971 V1 EN
(Equation 161)
Set ZA to 0.19
2
20
' 0.25 0.5
200
d
ZB jX j j ohm
= = × =
EQUATION1972 V2 EN
(Equation 162)
This corresponds to:
0.5
0.25 0.25 90
2.0
j
ZB j pu pu
= = = Ð °
EQUATION1973 V1 EN
(Equation 163)
Set ZB to 0.25
2
20
0.15 0.3
200
T
ZC jX j j ohm
= = × =
EQUATION1974 V1 EN
(Equation 164)
This corresponds to:
0.3
0.15 0.15 90
2.0
j
ZC j pu pu
= = = Ð o
EQUATION1975 V2 EN
(Equation 165)
1MRK 502 071-UEN -
Section 8
Impedance protection
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062 273
Application manual