ABB RELION REX640 Technical Manual page 697

1MRS759142 C
REX640
Technical Manual
GUID-C6E44B83-5126-42A6-9C23-C81F7C0679CE V1 EN
Figure 381: Phase-segregated bus differential protection based on high-
impedance principle
CT secondary winding resistances (R
also shown in Figure 382.
Figure 382 demonstrates a simplified circuit consisting only of one incoming and
outgoing feeder. To keep it simple, the voltage-dependent resistor (R
The wiring resistances are presented as total wiring resistances R
R is the maximum wiring resistance concerning all incoming feeder
m1
sets, whereas R
outgoing feeder sets.
The lower part of Figure 382
system and no CT saturation.
) and connection wire resistances (R
in
is the maximum wiring resistance concerning all
m2
shows the voltage balance when there is no fault in the
Section 4
Protection functions
/2) are
m
) is not included.
u
and R .
m1 m2
691