Mho Impedance Supervision Logic Zsmgapc; Faulty Phase Identification With Load Encroachment Fmpspdis; Phase Selection/Quadrilateral Characteristic W. Settable Angle; Distance Zones Quad With High Speed Distance Protection Zmfpdis - ABB RET670 Product Manual

Transformer protection RET670 2.0
Product version: 2.0
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.
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 protection zone, quadrilateral characteristic,
separate 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.
ABB
Mho alternative quadrilateral characteristic is available.
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.
The distance protection zones can operate, independent of
each other, in directional (forward or reverse) or non-directional
mode.
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.
Distance zones quad with high speed distance protection
ZMFPDIS
The High speed distance protection (ZMFPDIS) is providing
sub-cycle, down towards half-cycle, operate time for basic
faults within 60% of the line length and up to around SIR 5. At
the same time, it is specifically designed for extra care during
difficult conditions in high voltage transmission networks, like
faults on long heavily loaded lines and faults generating heavily
distorted signals. These faults are handled with outmost
security and dependability, although sometimes with reduced
operating speed.
The ZMFPDIS function is a six zone full scheme protection with
three fault loops for phase-to-phase faults and three fault loops
for phase-to-earth faults for each of the independent zones,
which makes the function suitable in applications with single-
phase autoreclosing.
1MRK 504 141-BEN C
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