ABB Relion 670 Series Technical Reference Manual page 145

1MRK 505 208-UEN B
Technical reference manual
CTRLZA
CTRLZB
ZoneSel=
CtrlIncludes
ZoneSel=
CtrlExcludes
ZoneSel=
FixedToZA
ZoneSel=
FixedToZB
ZoneSel=
FixedToZA&-ZB
IEC06000066 V1 EN
Figure 63: Zone selection logic
Description of invert current and forcing current to zero
This logic is intended for binary input signals that give possibility to force current
to zero or invert the current. Two settable delays on timer tZeroCurrent and
tInvertCurrent are also implemented making sure that the right decision is taken,
see figure 64.
tZeroCurrent
ZEROCUR
t
tInvertCurrent
INVCUR
t
CTConnection
Connected= 1
NotConnected= 0
ConnInverted= -1
A/D Conversion,
Multiplication with CT Ratio,
Taking in account setting
CTStarPoint for TRM
IED
CT Input
IEC06000068 V2 EN
Figure 64: Overall CT status
5 ms
&
³1
t
&
5 ms
&
³1
t
&
0.0
T
F
-1.0
T
1.0
F
X
Bayxx Current in
Primary Amperes
Section 5
Differential protection
CTtoZoneA-cont.
³1
CTtoZoneB-cont.
³1
StrtLoadTransfBayxx-cont.
&
InvertCTtoZoneB-cont.
en06000066.vsd
CurrentBayxx-cont.
X
IEC06000068_2_en.vsd
139