Siemens siprotec 7SA6, Manual

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Functions
6-55
7SA6 Manual
C53000-G1176-C156-2
6.2.4 Distance Protection with Polygonal Tripping Characteristic (optional)
6.2.4.1 Method of Operation
Operating
Polygons A tripping characteristic in the shape of a polygon is defined for each of the distance
zones. In total, there are five independent zones and one additional controlled zone
for each fault impedance loop. In Figure 6-29 the shape of a polygon is illustrated. The
first zone is shaded and forward directional, the third zone is reverse directional.
In general, the polygon is defined by means of a parallelogram which intersects the
axes with the values R and X as well as the tilt
ϕ
Line
. A load trapezoid with the setting
R
Load
und
ϕ
Load
may be used to cut the area of the load impedance out of the polygon.
The axial coordinates can be set individually for each zone;
ϕ
Line
, R
Load
und
ϕ
Load
are
common for all zones. The parallelogram is symmetrical with respect to the origin of
the R–X–coordinate system; the directional characteristic however limits the tripping
range to the desired quadrants (refer to “Direction Determination” below).
The R-reach may be set separately for the phase–phase faults and the phase–earth
faults to achieve a larger fault resistance coverage for earth faults if this is desired.
For the first zone an additional tilt
α
exists, which may be used to prevent overreach
resulting from angle variance and/or two ended infeed to short-circuits with fault resist-
ance. For Z1B and the higher zones this tilt does not exist.
3813 Dis.TripZ1B1p Distance TRIP single-phase Z1B
3825 DisTRIP3p.Z1Bsf DisTRIP 3phase in Z1B with single-ph Flt
3826 DisTRIP3p Z1Bmf DisTRIP 3phase in Z1B with multi-ph Flt.
3816 Dis.TripZ2/1p Distance TRIP single-phase Z2
3817 Dis.TripZ2/3p Distance TRIP 3phase in Z2
3818 Dis.TripZ3/T3 Distance TRIP 3phase in Z3
3821 Dis.TRIP 3p. Z4 Distance TRIP 3phase in Z4
3822 Dis.TRIP 3p. Z5 Distance TRIP 3phase in Z5
3850 DisTRIP Z1B Tel DisTRIP Z1B with Teleprotection scheme
3819 Dis.Trip FD-> Dist.: Trip by fault detection, forward
3820 Dis.Trip <-> Dist.: Trip by fault detec, rev/non-dir.
F.No. Alarm Comments