ABB Relion 670 series, Technical Reference Manual

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ZMQPDIS (21) together with Phase selection with load encroachment FDPSPDIS (21)
has functionality for load encroachment, which increases the possibility to detect high
resistive faults on heavily loaded lines, as shown in figure
73 .
en05000034.vsd
R
X
Forward
operation
Reverse
operation
IEC05000034 V1 EN
Figure 73: Typical quadrilateral distance protection zone with Phase selection
with load encroachment function FDPSPDIS (21) 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 autoreclosing.
Built-in adaptive load compensation algorithm prevents overreaching of zone 1 at load
exporting end at phase-to-ground faults on heavily loaded power lines.
The distance protection zones can operate independently 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.
6.1.3 Principle of operation
6.1.3.1 Full scheme measurement
The execution of the different fault loops within the IED are of full scheme type, which
means that each fault loop for phase-to-ground faults and phase-to-phase faults for
forward and reverse faults are executed in parallel.
Section 6
1MRK505222-UUS C
Impedance protection
174
Technical reference manual