ABB RELION REX640 Technical Manual page 969

1MRS759142 F
~
Figure 541: The fault loop impedance model for three-phase impedance measuring
element
R
1
X
1
R
F
The time delay of operation is defined with the
5) setting. The timer can be disabled with the setting
"False". This blocks the OPERATE_Zx (x = 1... 5) output of the three-phase measuring
elements.
Entering the line reach
The line reach is entered in primary ohms. The impedance format is selected
with
magnitude and angle.
Impedance mode Zn = Rectangular
In case of phase-to-phase or three-phase impedance measuring elements, the line
reach is defined with:
• Resistive reach:
• Reactive reach:
In case of non-directional characteristics, the reactive reach in reverse direction is
defined with the
denoted as α, is the same for both forward and reverse direction.
REX640
Technical Manual
R X
1 1
Positive-sequence resistance from measuring point to fault location
Positive-sequence reactance from measuring point to fault location.
Physical fault resistance per phase, for example, arc resistance.
The three-phase impedance measuring element measures the physical
fault resistance per phase. The resistive reach setting is common for
three-phase and phase-to-phase impedance measuring elements.
Impedance mode Zn = "Rectangular" for the vectors R, X and "Polar" for the
R1 zone x (x = 1...5)
X1 zone x (x = 1...5)
X1 reverse zone x (x = 1...5) setting. The characteristic line angle,
X
X
1
R
F
PP operate delay Znx (x = 1...
Protection functions
R
F
R
R
1
PP Op delay Mod Znx =
969