Section 7
Impedance protection
IEC05000034 V1 EN-US
Figure 67: Typical quadrilateral distance protection zone with Phase selection with load
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.
7.1.3
Function block
I3P*
V3P*
BLOCK
LOVBZ
BLKTR
PHSEL
DIRCND
ANSI06000256 V2 EN-US
Figure 68: ZMQPDIS (21) function block
178
X
Forward
operation
Reverse
operation
en05000034.vsd
encroachment function FDPSPDIS (21) activated
ZMQPDIS (21)
TRIP
TR_A
TR_B
TR_C
PICKUP
PU_A
PU_B
PU_C
PHPUND
ANSI06000256-2-en.vsd
R
1MRK 502 066-UUS B
IP12800-1 v2
SEMOD115983-4 v8
Technical manual