Micom P634 - Idiff>>> Threshold; Applying Current Transformer Supervision; Measured Operating Data of Ground Differential Protection

3.22.4.3 “High impedance” Operating Mode
This operating mode is provided for application with the high impedance current
measuring approach. The pick-up sensitivity is set via the I
diff>
parameter which
is already available.
3.22.5 Idiff>>> Threshold
The restraining quantity is no longer taken into account when the differential
current value exceeds the threshold set at REF_1: Idiff>>> PSx. Therefore
the P634 will issue a trip signal independently of the restraining quantity.
3.22.6 Applying Current Transformer Supervision
When applying current transformer supervision (CTS), the ground differential
protection function may be blocked for the relevant end where a CT fault is
detected. See details given in Section 3.29, (p. 3-196).
The CTS will now be presented using the transformer end a in combination with
function group REF_1 as an example. Equivalent considerations apply to other
transformer ends and function groups REF_2 and REF_3.
When a CTS: Alarm end a signal is issued, the associated ground differential
protection function is then blocked, if it has been set accordingly (REF_1: CTS
effective PSx = Yes by assigning REF_1 to end a).
64Z6022A
IN,a
REF_1:
IR,m2 PSx
[ * ]
REF_1:
m2 PSx
[ * ]
REF_1:
m1 PSx
[ * ]
REF_1:
Idiff> PSx
[ * ]
REF_1:
Idiff>>> PSx
[ * ]
kam,N,a⋅IN,a
kam,Y,a⋅IY,a
Id,N,a
IR,N,a
REF_1:
Trip signal
[ 041 005 ]
REF_1:
IR,N,a
402 551
REF_1:
Id,N,a
402 550
MAIN:
Protection active
306 001
REF_1:
Enabled
[ 041 132 ]
IA,a
IB,a
IC,a
IY,a
Parameter
set 1
set 2
set 3
set 4
REF_1:
m2 PSx
072 163
073 163
074 163
075 163
REF_1:
m1 PSx
072 162
073 162
074 162
075 162
REF_1:
Idiff> PSx
072 150
073 150
074 150
075 150
REF_1:
IR,m2 PSx
072 164
073 164
074 164
075 164
REF_1:
Idiff>>> PSx
072 151
073 151
074 151
075 151
CTS:
Alarm end a
[ 036 205 ]
1: Yes
REF_1:
CTS effective PSx
[ 080 003 ]
1: Yes
Fig. 3-103: Measuring system of the P634, shown here for REF_1
3.22.7 Measured Operating Data of Ground Differential Protection
The differential and restraining currents are displayed as measured operating
data provided that the set thresholds are exceeded.
P634
3 Operation
3-148 P634/EN M/R-42-A // P634‑311‑653