ABB REL670 Product Manual page 28

Line distance protection REL670 2.2
Product version: 2.2
X
Reverse
operation
IEC05000034 V1 EN
Figure 10. Typical quadrilateral distance protection zone with Phase
selection, quadrilateral characteristic with settable angle
function FRPSPDIS activated
The independent measurement of impedance for each fault
loop together with a sensitive and reliable built in phase
selection makes the function suitable in applications with single
phase auto-reclosing.
The distance protection zones can operate, independent of
each other, in directional (forward or reverse) or non-directional
mode. This makes them suitable, together with different
communication schemes, for the protection of power lines and
cables in complex network configurations, such as parallel
lines, multi-terminal lines.
Directional impedance element for Mho characteristic
ZDMRDIR
The phase-to-earth impedance elements can be optionally
supervised by a phase unselective directional function (phase
unselective, because it is based on symmetrical components).
Mho impedance supervision logic ZSMGAPC
The Mho impedance supervision logic (ZSMGAPC) includes
features for fault inception detection and high SIR detection. It
also includes the functionality for loss of potential logic as well
as for the pilot channel blocking scheme.
ZSMGAPC can mainly be decomposed in two different parts:
1. A fault inception detection logic
2. High SIR detection logic
Faulty phase identification with load encroachment FMPSPDIS
The ability to accurately and reliably classify different types of
fault so that single phase tripping and autoreclosing can be
used plays an important roll in today's power systems.
28
Forward
operation
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en05000034.vsd
The phase selection function is design to accurately select the
proper fault loop(s) in the distance function dependent on the
fault type.
The heavy load transfer that is common in many transmission
networks may in some cases interfere with the distance
protection zone reach and cause unwanted operation.
Therefore the function has a built in algorithm for load
encroachment, which gives the possibility to enlarge the
resistive setting of the measuring zones without interfering with
the load.
The output signals from the phase selection function produce
important information about faulty phase(s), which can be used
for fault analysis as well.
Distance measuring zone, quad characteristic separate Ph-Ph
and Ph-E settings ZMRPDIS, ZMRAPDIS
The line distance protection is up to five zone full scheme
protection with three fault loops for phase-to-phase faults and
three fault loops for phase-to-earth fault for each of the
independent zones. Individual settings for each zone in resistive
and reactive reach gives flexibility for use as back-up protection
for transformer connected to overhead lines and cables of
different types and lengths.
Mho alternative quadrilateral characteristic is available.
Distance protection zone, quadrilateral characteristic
(ZMRPDIS) together with Phase selection, quadrilateral
characteristic with settable angle (FRPSPDIS) has functionality
for load encroachment, which increases the possibility to
detect high resistive faults on heavily loaded lines, as shown in
figure 7.
X
Reverse
operation
IEC05000034 V1 EN
Figure 11. Typical quadrilateral distance protection zone with Phase
selection, quadrilateral characteristic with settable angle
function FRPSPDIS activated
1MRK 506 372-BEN -
Forward
operation
R
en05000034.vsd
ABB