
CHAPTER 7: PROTECTION
GROUPED PROTECTION ELEMENTS
D90
PLUS
LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
187
Figure 163: Phase distance configuration window (example)
The following settings are available for each phase distance zone. There are five phase
distance zones of protection in each setting group.
Function
Range: Enabled, Disabled
Default: Enabled
This setting enables and disables the phase distance protection feature.
Direction
Range: Forward, Reverse, Non-Directional
Default: Forward
All phase distance zones are reversible. The forward direction is defined by the
RCA
setting, whereas the reverse direction is shifted 180° from that angle. The non-
directional zone spans between the forward reach impedance defined by the
Reach
and
RCA
settings, and the reverse reach impedance defined by
Reverse Reach
and
Reverse
Reach RCA
settings.
Shape
Range: Mho, Quad
Default: Mho
This setting selects the shape of the phase distance function between the mho and
quadrilateral characteristics. The selection is available on a per-zone basis. The two
characteristics and their possible variations are shown in the following figures.