Sel 411L - Figure 3.126 Zones 3, 4, and 5 Quadrilateral Ground-Distance Element Logic; Mho Phase Distance Elements

P.3.186
SEL-411L Relay Protection Manual Date Code 20151029
Protection Functions
Mho Phase Distance Elements
Figure 3.126 Zones 3, 4, and 5 Quadrilateral Ground-Distance Element Logic
Mho Phase Distance Elements
The relay has five independent zones of mho phase distance protection. The
mho phase distance protection operates for phase-to-phase, phase-to-phase-to-
ground, and three-phase faults. Set the reach for each zone independently.
Zone 1 and Zone 2 distance elements are forward only, while you can set
Zones 3–5 distance elements either forward or reverse. The mho phase
distance elements use positive-sequence voltage polarization for increased
reliability and also generate a dynamic expanding mho characteristic that
provides additional fault resistance coverage.
NOTE: The -0 relay provides fast and
secure tripping but does not have
high-speed distance elements. Typical
detection time for the -0 relay is
1.5 cycles.
The relay has five independent zones of quadrilateral phase distance
protection (see Quadrilateral Phase Distance Elements). Although the mho
and quadrilateral phase elements are independent, you can enable both at the
same time. To this end, the outputs from the mho and quadrilateral phase
elements are ORed to a single protection output (see Figure 3.125,
Figure 3.128, and Figure 3.129).
—
+
—
+
(Setting)
(Setting)
(Setting)
XGPOL := IG
32VE
XAGn
32QE
32GF
XGPOL := I2
DIRn := F
XGPOL := IG
32VE
(Setting)
(Setting)
32QE
32GR
XGPOL := I2
xAGR > —XGn
—RGn < rAGR < RGn
3PO
FSA
ILOP
VPOLV
xAGF < XGn
—RGn < rAGF < RGn
0.1 • I
nom
IGL
IAL
SPO
(Relay Word Bit)
Zone 3, 4, and 5 Quadrilateral Ground
Distance Logic for A-phase.
B- and C-Phase Logic Is Similar.
n = 3, 4, or 5
Relay
Word Bit
Relay
Word Bit
Relay
Word Bit
Relay
Word Bit
ARESE = N
ENX2AG