Load Encroachment - ABB REL650 series Technical Manual

Section 6
Impedance protection
6.2.6.4
136
×
4 X1
3
0.5·RFltFwdPP·K3
X1·K3
0.5·RFltRevPP·K3
2
=
K3
3
ANSI05000671 V4 EN
Figure 55: The characteristic of FDPSPDIS (21) for three-phase fault (setting
parameters in italic)

Load encroachment

Each of the six measuring loops has its own load encroachment characteristic based on the
corresponding loop impedance. The load encroachment functionality is always active, but
can be switched off by selecting a high setting.
The outline of the characteristic is presented in figure 56. As illustrated, the resistive
blinders are set individually in forward and reverse direction while the angle of the sector
is the same in all four quadrants.
X (ohm/phase)
90 deg
2 RFltFwdPP
30 deg
ANSI05000671-4-en.vsd
1MRK 506 335-UUS A
×
3
R (ohm/phase)
Technical manual