ABB RELION REF615R Technical Manual page 144

Section 4
Protection functions
138
The operation of 67/51P and 67/50P can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
V_A_AB
V_B_BC
V_C_CA
V
1
V
2 Directional
calculation
I
2
I_A
I_B
I_C
NON_DIR
Level
detector
ENA_MULT
BLOCK
GUID-92621351-8DF2-4606-A043-F79C018C12A4 V2 EN
Figure 64: Functional module diagram
Directional calculation
The directional calculation compares the current phasors to the polarizing phasor. A
suitable polarization quantity can be selected from the different polarization quantities,
which are the positive sequence voltage, negative sequence voltage, self-polarizing
(faulted) voltage and cross-polarizing voltages (healthy voltages). The polarizing method
is defined with the Pol quantity setting.
Table 95: Polarizing quantities
Polarizing quantity
Pos. seq. volt
Neg. seq. volt
Self pol
Cross pol
The directional operation can be selected with the Directional mode setting. The user can
select either "Non-directional", "Forward" or "Reverse" operation. By setting the value of
Phase
selection
logic
Timer
t
t
Blocking
logic
Description
Positive sequence voltage
Negative sequence voltage
Self polarization
Cross polarization
1MRS240050-IB C
TRIP
PICKUP
REF615R
Technical Manual