Full-Scheme Distance Measuring, Mho Characteristic Zmhpdis; Full-Scheme Distance Protection, Quadrilateral For Earth Faults - ABB RED670 Product Manual

Line differential protection RED670 2.1 IEC
Product version: 2.1
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 a four zone full
scheme protection for back-up detection of short circuit and
earth faults. The numerical mho line distance protection is a
three zone full scheme protection for back-up detection of short
circuit and earth faults.
The four 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.
jX
Operation area Operation area
Operation area
No operation area No operation area
IEC07000117-2-en.vsd
IEC07000117 V2 EN
Figure 13. Load encroachment influence on the offset mho
characteristic
The distance protection zones can operate, independent of
each other, in directional (forward or reverse) or non-directional
26
R
mode (offset). 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.
The possibility to use the phase-to-earth quadrilateral
impedance characteristic together with the mho characteristic
increases the possibility to overcome eventual lack of sensitivity
of the mho element due to the shaping of the curve at remote
end faults.
The integrated control and monitoring functions offer effective
solutions for operating and monitoring all types of transmission
and sub-transmission lines.

Full-scheme distance protection, quadrilateral for earth faults

ZMMPDIS, ZMMAPDIS
The line distance protection is an up to five (depending on
product variant) zone full scheme protection function with 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.
The Full-scheme distance protection, quadrilateral for earth
fault functions have functionality for load encroachment, which
increases the possibility to detect high resistive faults on heavily
loaded lines , see Figure 11.
X
Reverse
operation
IEC05000034 V1 EN
Figure 14. 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
phase auto-reclosing.
1MRK 505 346-BEN -
Forward
operation
R
en05000034.vsd
ABB