Hitachi Relion REL670 Product Manual page 36

Line distance protection REL670
Version 2.2
X
Reverse
operation
IEC05000034 V1 EN-US
Figure 8. 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
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. 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.
36
Forward
operation
R
en05000034.vsd
© 2017 - 2022 Hitachi Energy. All rights reserved
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. Each zone
is an individual function block available for independent
configuration in ACT.
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 9.
Load compensation algorithm prevents overreaching at
phase-to-earth faults on heavily loaded power lines, see
Figure 9. This Load encroachment characteristic is taken
M13139-3 v9
from the FMPSPDIS function.
jX
Operation area
Operation area
No operation area
IEC07000117 V2 EN-US
Figure 9. Load encroachment influence on the offset mho characteristic
1MRK 506 372-BEN Q
Operation area
R
No operation area
IEC07000117-2-en.vsd
SEMOD175459-4 v12
Hitachi Energy