Hitachi Relion 670 Series Product Manual page 37

Line differential protection RED670
Version 2.2
Distance measuring zone, quadrilateral characteristic
for series compensated lines ZMCPDIS, ZMCAPDIS
The line distance protection is an up to five (depending on
product variant) 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 resistive and reactive
reach give flexibility for use on overhead lines and cables of
different types and lengths.
Quadrilateral characteristic is available.
Distance measuring zone, quadrilateral characteristic for
series compensated lines (ZMCPDIS) function has
functionality for load encroachment which increases the
possibility to detect high resistive faults on heavily loaded
lines.
X
Reverse
operation
IEC05000034 V1 EN-US
Figure 12. Typical quadrilateral distance protection zone with load
encroachment function 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.
Built-in adaptive load compensation algorithm for the
quadrilateral function prevents overreaching of zone1 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.
Phase selection, quadrilateral characteristic with
fixed angle FDPSPDIS
The operation of transmission networks today is in many
cases close to the stability limit. Due to environmental
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Forward
operation
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considerations, the rate of expansion and reinforcement of
the power system is reduced, for example, difficulties to get
SEMOD168173-4 v11
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. Phase selection,
quadrilateral characteristic with fixed angle (FDPSPDIS) 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, FDPSPDIS 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.
Full-scheme distance measuring, Mho characteristic
ZMHPDIS
The numerical mho line distance protection is an up to five
(depending on product variant) zone full scheme protection
of short circuit and earth faults.
The zones have fully independent measuring and settings,
which gives high flexibility for all types of lines.
The IED can be used up to the highest voltage levels. It is
suitable for the protection of heavily loaded lines and multi-
terminal lines where the requirement for tripping is one-,
two- and/or three-pole.
The independent measurement of impedance for each fault
loop together with a sensitive and reliable phase selection
makes the function suitable in applications with single
phase autoreclosing.
Built-in selectable zone timer logic is also provided in the
function.
Adaptive load compensation algorithm prevents
overreaching at phase-to-earth faults on heavily loaded
power lines, see Figure 13.
M13139-3 v9
1MRK 505 379-BEN R
SEMOD175459-4 v12
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