ABB RELION REF615R, Technical Manual

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V_A_AB
BLOCK
U_LO
27R
V_B_BC
V_C_CA
Pickup value
Max(I_A , I_B , I_C)
1.0 p.u.
1.0 p.u.
I_DIFF
2.0 p.u. 3.0 p.u. 4.0 p.u.
Max trip current
NON-OPERATE OPERATE
GUID-D083BF22-574C-4603-971F-5F4371632A28 V2 EN
Figure 191: CCM operating characteristics
When the differential current I_DIFF is in the operating region, the
FAIL
output is
activated.
The function is internally blocked if any phase current is higher than the set Max trip
current . When the internal blocking activates, the
FAIL
output is deactivated
immediately. The internal blocking is used for avoiding false operation during a fault
situation when the current transformers are saturated due to high fault currents.
The value of the differential current is available in the monitored data view on the LHMI
or through other communication tools. The value is calculated with the equation.
I DIFF I A I B I C I REF
_ _ _ _ _
= + + −
GUID-9CC931FA-0637-4FF8-85D4-6F461BD996A9 V2 EN
(Equation 21)
The Pickup value setting is given in units of ×In of the phase current transformer. The
possible difference in the phase and reference current transformer ratios is internally
compensated by scaling
I_REF
with the value derived from the Primary current setting
values. These setting parameters can be found in the Basic functions section.
The activation of the
BLOCK
input deactivates the
FAIL
output immediately.
Section 6
1MRS240050-IB C
Supervision functions
364 REF615R
Technical Manual