~
~
~
A
B
C
Uo
E
A
E
B
E
C
Io
Reverse
Fault
Y
Fd
L
cc
R
cc
Y
Bg
I
eFd
(I
eTot
‐
I
eFd
)
R
n
Protected
feeder
Background network
Im(Yo)
Re(Yo)
Reverse fault:
Yo
≈ ‐
j*I
eFd
/U
ph
VG
Vph
IG
GUID-2C307D73-EF4A-479A-A6E5-47CAC730188C V1 EN
Figure 176:
Admittance calculation during a reverse fault
R
CC
Resistance of the parallel resistor
L
CC
Inductance of the compensation coil
R
n
Resistance of the neutral grounding resistor
Y
Fd
Phase-to-ground admittance of the protected feeder
Y
Bg
Phase-to-ground admittance of the background network
For example, in a 15 kV compensated network with the magnitude of the ground-fault
current in the protected feeder being 10 A (Rf = 0 Ω), the theoretical value for the
measured admittance during a ground fault in the reverse direction, that is, outside the
protected feeder, can be calculated.
Section 4
1MAC059074-MB A
Protection functions
376
615 series ANSI
Technical Manual
Summary of Contents for Relion 615 series
Page 1: ... RELION PROTECTION AND CONTROL 615 series ANSI Technical Manual ...
Page 2: ......
Page 39: ...Section 17 Glossary 1181 Table of contents 615 series ANSI 33 Technical Manual ...
Page 40: ...34 ...
Page 64: ...58 ...
Page 216: ...210 ...
Page 884: ...878 ...
Page 1038: ...1032 ...
Page 1136: ...1130 ...
Page 1172: ...1166 ...
Page 1180: ...1174 ...
Page 1186: ...1180 ...
Page 1192: ...1186 ...
Page 1193: ...1187 ...
Page 1194: ......
Page 1195: ......