ABB RER620

1MAC309294-MB F Section 4
Protection functions
RER620 101
Technical Manual
67/50P-1 and high stage 67/50P-2 can be selected to be either definite time (DT) or inverse
definite minimum time (IDMT).
In the DT mode, the function trips after a predefined trip time and resets when the fault
current disappears. The IDMT mode provides current-dependent timer characteristics.
The function contains a blocking functionality. It is possible to block function outputs,
timers or the function itself, if desired.
4.1.2.4 Operation principle
The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are “Enable” and “Disable.”
The single-phase directional overcurrent protection function is used as one-phase and
three-phase overcurrent and short circuit protection. The phase-tripping mode is selected
with the Configuration setting Recloser type.
The operation in either tripping mode can be described by using a module diagram (see
Figure 41). Some modules have different functionality depending on whether the function
is in one-phase or three-phase tripping mode. All the blocks in the diagram are explained
in the next sections.
Figure 41: Functional module diagram
Directional calculation
The directional calculation compares the current phasors to the polarizing phasor. The user
can select the suitable one from different polarization quantities which are the positive
sequence voltage, negative sequence voltage, self polarizing (faulted) voltage and cross
TRIP_C
Level
detector
I_A
BLOCK
PICKUP_C
Blocking
logic
ENA_MULT
t
Timer
t
I
2
V
2
V
1
NON_DIR
Directional
calculation
TRIP_B
PICKUP_B
t
Timer
t
TRIP_A
PICKUP_A
t
Timer
t
Phase
Selection
logic
V_A_AB
V_B_BC
V_C_CA
I_B
I_C