ABB Relion 650 Series Applications Manual page 68

Section 6
Differential protection
Table 8:
Operating
voltage
TripPickup
20 V
40 V
60 V
80 V
100 V
150 V
200 V
Table 9:
Operating
voltage
TripPickup
20 V
40 V
60 V
80 V
100 V
150 V
200 V
The current transformer saturation voltage must be at least 2 ˣ
operating margin. This must be checked after calculation of
When the R value has been selected and the
scheme
to equation 9.
= ×
IP n IR
EQUATION1747 V1 EN-US
where:
n
IP
IR
Ires
ΣImag
62
1 A channels: input with minimum operating down to 40 mA
Stabilizing Operating
resistor R current level
ohms 1 A
500 0.040 A
1000 0.040 A
1500 0.040 A
2000 0.040 A
2500 0.040 A
3750 0.040 A
5000 0.040 A
5 A channels: input with minimum operating down to 200 mA
Stabilizing Operating
resistor R1 current level
ohms 5 A
100 0.200 A
200 0.200 A
300 0.200 A
400 0.200 A
500 0.200 A
750 0.200 A
1000 0.200 A
IP can be calculated. The sensitivity is decided by the total current in the circuit according
å
+ +
( Ires lmag )
is the CT ratio
primary current at IED pickup,
IED pickup current (U>Trip/SeriesResistor)
is the current through the non-linear resistorand
is the sum of the magnetizing currents from all CTs in the circuit (for example, 4 CTs
for restricted earth fault protection, 2 CTs for reactor differential protection, 3-5 CTs
for autotransformer differential protection , the number of feeders, including the
buscoupler, for busbar differential protection).
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Stabilizing Operating
resistor R current level
ohms 1 A
-- --
-- --
600 0.100 A
800 0.100 A
1000 0.100 A
1500 0.100 A
2000 0.100 A
Stabilizing Operating
resistor R1 current level
ohms 5 A
-- --
100 0.400
150 0.400 A
200 0.400 A
250 0.400 A
375 0.400 A
500 0.400 A
TripPickup .
TripPickup value has been set, the sensitivity of the
1MRK 505 287-UUS B
TripPickup to have sufficient
Busbar protection REB650
Application manual
(Equation 9)