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Setting self-impedances
With regard to the self-impedances, the user should set the resistance of the self-
impedances for settings [FL_Raa], [FL_Rbb] and [FL_Rcc] and set the reactance of the
self-impedances for settings [FL_Xaa], [FL_Xbb] and [FL_Xcc].
Setting mutual-impedances
With regard to setting the mutual-impedances, the user should set the resistance of the
mutual-impedance for settings [FL_Rab], [FL_Rbc] and [FL_Rca] and set the reactance
of the mutual-impedances for settings [FL_Xab], [FL_Xbc], and [FL_Xca].
Setting compensation factors
If imbalanced impedances are considered, Equations (2.26-10) and (2.26-11) are used
to acquire the zero-sequence and positive-sequence impedances. The calculations are
executed internally by the FL function; thus, the user does not need to consider them
in the matrix setting mode.
Assumption of fault direction
(iii)
The user can select the direction for the FL computation to be in either the forward or the
reverse direction. When the forward direction is selected, other protection elements related to
the FL computation should have the same direction If the user selects the reverse direction,
other corresponding functions should have the reverse direction. Otherwise, the FL
computation will fail to start.
Figure 2.26-3 illustrates the relationship between the location of faults relative to the
direction of FL computations. The user should set the scheme switch [FL_Dir] Forward if the
fault location computation is required for faults that occur in the forward direction. Conversely,
set [FL_Dir] Reverse if the fault location computation is required for faults that occur in the
reverse direction.
Bus G
IED
IEF
a. Fault in Forward direction
Figure 2.26-3 Forward fault and reverse fault
Fault
I f
- 301 -
Bus G
Fault
I f
IED
IEF
b. Fault in Reverse direction
6F2T0207 (0.01)
GRE200 (5,6)
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