The most typical
application
YNdx
d
CB
CT
CT
CB
Y
IED
CB
CB
CB
CB
Autotransformer
The most complicated
application - autotransformer
CT
CT
CT
CT
IEC05000058-2-en.vsd
IEC05000058-2 V1 EN-US
Figure 5.
Examples of applications of the REFPDIF
4. Impedance protection
Full-scheme distance measuring, Mho characteristic
ZMHPDIS
SEMOD175459-4 v12
The numerical mho line distance protection is an up to four
zone full scheme protection for back-up detection of short
circuit and earth faults.
The full scheme technique provides back-up protection of
power lines with high sensitivity and low requirement on
remote end communication.
The zones have fully independent measuring and settings,
which gives high flexibility for all types of lines.
Built-in selectable zone timer logic is also provided in the
function.
The function can be used as under impedance back-up
protection for transformers and generators.
Directional impedance element for Mho characteristic
ZDMRDIR
SEMOD175532-4 v2
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).
High speed distance protection, quadrilateral and mho
ZMFPDIS
GUID-2E34AB7F-886E-499F-8984-09041A89238D v7
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
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
GUID-C5C1ADD8-50A5-4485-848C-77D2222B56DC v7
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.
Pole slip protection PSPPPAM
SEMOD143246-4 v4
The situation with pole slip of a generator can be caused by
different reasons.
A short circuit may occur in the external power grid, close to
the generator. If the fault clearing time is too long, the
1MRK 502 068-BEN D
Generator protection REG670 2.1 IEC
Product version: 2.1
ABB
19
