IEC07000117-2-en.vsd
jX
Operation area Operation area
R
Operation area
No operation area No operation area
IEC07000117 V2 EN-US
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 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
SEMOD154544-4 v7
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
14.
en05000034.vsd
R
X
Forward
operation
Reverse
operation
IEC05000034 V1 EN-US
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.
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.
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).
Mho impedance supervision logic ZSMGAPC
SEMOD153843-5 v3
The Mho impedance supervision logic (ZSMGAPC)
includes features for fault inception detection and high
SIR detection. It also includes the functionality for loss
of potential logic as well as for the pilot channel
blocking scheme.
ZSMGAPC can mainly be decomposed in two different
parts:
1. A fault inception detection logic
2. High SIR detection logic
Line differential protection RED670
1MRK 505 379-BEN N
34 Hitachi Power Grids
© Copyright 2017 Hitachi Power Grids. All rights reserved
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