Hitachi Relion REL670 Product Manual page 38

Line distance protection REL670
Version 2.2
possibility to detect high resistive faults on heavily loaded
lines, as shown in figure 11.
X
Reverse
operation
IEC05000034 V1 EN-US
Figure 11. 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 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.
38
Forward
operation
R
en05000034.vsd
GUID-09D0E480-C003-424E-BECD-A82BCB0052CD v1
© 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.
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
seven 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 for applications with single-phase
autoreclosing.
Each measurement zone is designed with the flexibility to
operate in either quadrilateral or mho characteristic mode.
This can be decided separately for the phase-to-earth or
phase-to-phase loops. Out of the seven zones, one zone
has fixed directionality to reverse, one zone has fixed
directionality to forward, and five zone with directionality
independently settable to forward/reverse/non-directional.
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.
The ZMFPDIS function is also equipped with the parallel
line mutual coupling compensation feature based on the
parallel line residual current.
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
seven 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
1MRK 506 372-BEN Q
GUID-2E34AB7F-886E-499F-8984-09041A89238D v11
GUID-C5C1ADD8-50A5-4485-848C-77D2222B56DC v10
Hitachi Energy