ABB REG670 Applications Manual page 279

1MRK 502 071-UEN -
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
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
UBase 20
= =
ZBase
SBase 200
EQUATION1969 V1 EN
= +
ZA Z transf ( ) Zsc network (
EQUATION1970 V1 EN
This corresponds to:
j 0.38
= =
ZA j 0.19 pu
2.0
EQUATION1971 V1 EN
Set ZA to 0.19
2
20
= = ×
ZB jX ' j 0.25
d
200
EQUATION1972 V2 EN
This corresponds to:
j 0.5
= =
ZB j 0.25 pu
2.0
EQUATION1973 V1 EN
Set ZB to 0.25
2
20
= = × =
ZC jX j 0.15
T
200
EQUATION1974 V1 EN
This corresponds to:
j 0.3
= =
ZC j 0.15 pu
2.0
EQUATION1975 V2 EN
2
=
2.0 ohm
2 2
20 20
= × +
) j 0.15 j
200 5000
= Ð °
0.19 90 pu
=
j 0.5 ohm
= Ð °
0.25 90 pu
j 0.3 ohm
= Ð
o
0.15 90 pu
Section 8
Impedance protection
=
j 0.38 ohm
(Equation 159)
(Equation 160)
(Equation 161)
(Equation 162)
(Equation 163)
(Equation 164)
(Equation 165)
273