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1MRK 506 369-UEN B
17.1.2.2
Line distance protection REL670 2.2 IEC
Application manual
Single- and/or three-phase tripping
The single-/three-phase tripping operation mode will give single-phase tripping for
single-phase faults and three-phase tripping for multi-phase fault. This operating
mode is always used together with a single-phase autoreclosing scheme.
The single-phase tripping operation mode can include different options and the use
of the different inputs in the function block. Inputs TRINL1, TRINL2 and TRINL3
shall be used for trip signals from functions with built-in phase selection logic such
as distance or line differential protection functions.
The inputs 1PTRZ and 1PTREF are used for single-phase tripping from functions
which do not have built-in phase selection logic:
•
1PTRZ can be connected to the carrier aided trip signal from the distance
protection scheme (it means that another distance protection function has seen
or detected the fault)
•
1PTREF can be connected to an earth fault function such as EF4PTOC or a
carrier aided trip signal from the earth fault protection scheme
These two inputs are combined with the external phase selection logic. Phase
selection signals from the external phase selector must be connected to the inputs
PSL1, PSL2 and PSL3 to achieve the tripping on the respective single-phase trip
outputs TRL1, TRL2 and TRL3. The output TRIP is a general trip and is always
activated independent of which phase is involved. Depending on which phases are
involved the outputs TR1P, TR2P and TR3P will be activated as well.
When single-phase tripping schemes are used, a single-phase autoreclosing attempt
is expected to follow. For cases where the autoreclosing is not in service or will not
follow for some reason, the input prepare three-phase trip P3PTR must be
activated. This input is normally connected to the output PREP3P on the
autorecloser function SMBRREC but can also be connected to other signals, for
example, an external logic signal. If two circuit breakers are involved, one
SMPPTRC block instance and one SMBRREC instance are used for each circuit
breaker. This will ensure correct operation and behavior of each circuit breaker.
The output TR3P must be connected to the input TR3P on the SMBRREC function
in order to switch SMBRREC to perform a three-phase reclosing. If this signal is
not activated, SMBRREC will use single-phase dead time.
If a second line protection is utilizing the same SMBRREC, the
three-phase trip signal must be generated as OR conditions from
both line protections.
Other back-up functions are connected to the input TRIN as described above for
three-phase tripping. A typical connection for a single-phase tripping scheme is
shown in figure 383.
Section 17
Logic
M14828-11 v7
743
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