17.1.2.2 Single- and/or three-pole tripping
The single-/three-pole tripping will give single-pole tripping for single-phase faults and
three-pole tripping for multi-phase fault. The operating mode is always used together with
a single-phase autoreclosing scheme.
The single-pole tripping can include different options and the use of the different inputs
in the function block. Inputs TRINP_A, TRINP_B and TRINP_C shall be used for trip
signals from functions with built-in pole selection logic such as distance or line
differential protection functions.
The inputs 1PTRZ and 1PTRGF are used for single-pole tripping from functions which do
not have built-in pole selection logic:
• 1PTRZ is connected to communication receive from distance protection scheme (it
means that another distance protection function has seen or detected the fault)
• 1PTRGF trip by ground fault protection via communication scheme to provide
single-pole tripping
These two inputs are combined with the external phase selection logic. Phase selective
signals from the external phase selector must be connected to the inputs PS_A, PS_B and
PS_C to achieve the tripping on the respective single-pole trip outputs TR_A, TR_B and
TR_C. 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-pole 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-pole trip P3PTR must be activated. This input is
normally connected to the output PREP3P on the autorecloser function SMBRREC (79)
but can also be connected to other signals, for example, an external logic signal. If two
breakers are involved, one SMPPTRC block instance and one SMBRREC (79) instance
are used for each breaker. This will ensure correct operation and behavior of each breaker.
The output TR3P must be connected to the input TR3P on the SMBRREC (79) function
in order to switch SMBRREC (79) to perform a three-pole reclosing. If this signal is not
activated, SMBRREC will use single-pole dead time.
If a second line protection is utilizing the same SMBRREC (79), the three-
pole trip signal must be generated as OR conditions from both line
protections.
1MRK 506 369-UUS - Section 17
Logic
Line distance protection REL670 2.2 ANSI 793
Application manual
To Next Page
Loading...
