ABB REL670 Product Manual page 29

Line distance protection REL670 2.2
Product version: 2.2
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
pole tripping and autoreclosing.
Built-in adaptive load compensation algorithm prevents
overreaching of zone 1 at load exporting end at phase-to-earth
faults on heavily loaded power lines.
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 and so on.
Phase selection, quadrilateral characteristic with settable
angle FRPSPDIS
The operation of transmission networks today is in many cases
close to the stability limit. Due to environmental considerations,
the rate of expansion and reinforcement of the power system is
reduced for example, difficulties to get permission to build new
power lines. The ability to accurately and reliably classify the
different types of fault, so that single pole tripping and
autoreclosing can be used plays an important role in this
matter. The phase selection function is designed to accurately
select the proper fault loop in the distance function dependent
on the fault type.
The heavy load transfer that is common in many transmission
networks may make fault resistance coverage difficult to
achieve. Therefore, the function has a built in algorithm for load
encroachment, which gives the possibility to enlarge the
resistive setting of both the phase selection and the measuring
zones without interfering with the load.
The extensive output signals from the phase selection gives
also important information about faulty phase(s) which can be
used for fault analysis.
A current-based phase selection is also included. The
measuring elements continuously measure three phase
currents and the residual current and, compare them with the
set values.
High speed distance protection, quadrilateral and mho
ZMFPDIS
The high speed distance protection (ZMFPDIS) provides a sub-
cycle, down towards a half-cycle operate time. Its six zone, full
scheme protection concept is entirely suitable in applications
with single-phase autoreclosing.
Each measurement zone is designed with the flexibility to
operate in either quadrilateral or mho characteristic mode. This
can even be decided separate for the phase-to-ground or
phase-to-phase loops. The six zones can operate either
independent of each other, or their start can be linked (per
ABB
zone) through the phase selector or the first starting zone. This
can provide fast operate times for evolving faults.
The operation of the phase-selection is primarily based on a
current change criteria (i.e. delta quantities), however there is
also a phase selection criterion operating in parallel which
bases its operation on voltage and current phasors exclusively.
Additionally the directional element provides a fast and correct
directional decision under difficult operating conditions,
including close-in three-phase faults, simultaneous faults and
faults with only zero-sequence in-feed. During phase-to-earth
faults on heavily loaded power lines there is an adaptive load
compensation algorithm that prevents overreaching of the
distance zones in the load exporting end, improving the
selectivity of the function. This also reduces underreach in the
importing end.
High speed distance protection for series comp. lines, quad
and mho characteristic ZMFCPDIS
The high speed distance protection (ZMFCPDIS) provides a
sub-cycle, down towards a half-cycle operate time. Its six zone,
full scheme protection concept is entirely suitable in
applications with single-phase autoreclosing.
High speed distance protection ZMFCPDIS is fundamentally
the same function as ZMFPDIS but provides more flexibility in
zone settings to suit more complex applications, such as series
compensated lines. In operation for series compensated
networks, the parameters of the directional function are altered
to handle voltage reversal.
Each measurement zone is designed with the flexibility to
operate in either quadrilateral or mho characteristic mode. This
can even be decided separate for the phase-to-ground or
phase-to-phase loops. The six zones can operate either
independent of each other, or their start can be linked (per
zone) through the phase selector or the first starting zone. This
can provide fast operate times for evolving faults.
The operation of the phase-selection is primarily based on a
current change criteria (i.e. delta quantities), however there is
also a phase selection criterion operating in parallel which
bases its operation on voltage and current phasors exclusively.
Additionally the directional element provides a fast and correct
directional decision under difficult operating conditions,
including close-in three-phase faults, simultaneous faults and
faults with only zero-sequence in-feed.
During phase-to-earth faults on heavily loaded power lines
there is an adaptive load compensation algorithm that prevents
overreaching of the distance zones in the load exporting end,
improving the selectivity of the function. This also reduces
underreach in the importing end.
1MRK 506 372-BEN -
29