Teleprotection With Earth Fault Protection - Siemens siprotec 7SA6 User Manual

Permissive
Underreach
Transfer
Important for All
Schemes

8.3.12.2 Teleprotection with Earth Fault Protection

7SA6 Manual
C53000-G1176-C133-1
transmitting, the receiving end may not generate a trip signal, unless this results from
a higher distance stage. After removal of the simulated fault at the transmitting end,
the receiving end remains blocked for the additional duration of the transmit
prolongation time of the transmitting end (6HQG 3URORQJ, address ). The
transient blocking time of the receiving end (7U%ON %ORFN7LPH, address ) will
additionally appear if a finite waiting time 7U%ON :DLW 7LPH (address  ) was set
and if this time had been exceeded.
In case of a phase-segregated transmission the subsequent checks are carried out for
each phase. The correct phase allocation is also to be checked.
The test must be carried out at both line ends, on a three terminal line at each line end
for each transmission path. Please take note of the last margin heading "Important for
All Schemes"!
Prerequisite: 7HOHSURWHFWLRQ IRU 'LVWDQFH SURW 7HOHSURW 'LVW in
address  (Section 5.1) is set to the permissive underreach transfer trip mode, i.e.
3877 or 3877 3LFNXS ; furthermore the setting in address  must be set to
)&7 7HOHS () 21. Naturally the corresponding transmit and receive signals must
also be assigned to the corresponding binary output and input.
For more details about the function of the blocking scheme refer to Subsections
6.4.1.1 to 6.4.1.3. Communication between the line ends is necessary.
On the transmitting end, a fault in zone Z1 must be simulated. This can be achieved
with secondary injection test equipment.
Subsequently, on the receiving end in case of permissive underreach transfer 3877 a
fault is simulated inside Z1B, but for 3877 3LFNXS anywhere outside Z1. Tripping
takes place immediately, (or in T1B), without signal transmission only in a higher
distance stage. In case of direct transfer trip an immediate trip is always executed at
the receiving end.
In case of a phase-segregated transmission the above-mentioned checks are carried
out for each phase. The correct phase allocation is also to be checked.
The tests must be carried out at both line ends, on a three terminal line at each line
end for each transmission path. Please take note of the last margin heading "Important
for All Schemes"!
If the earth fault protection was disabled for the signal transmission tests, it may be re-
enabled now. If setting parameters were changed for the test (e.g. mode of the echo
function or timers for unambiguous observation of sequences), these must now be re-
set to the prescribed values.
This section is only relevant if the device is connected to a grounded system and earth
fault protection is applied. The device must therefore be provided with the earth fault
protection function according to its ordering code (position 16 in ordering code: 4 or 5
or 6 or 7). Address  (DUWK )DXOW 2& must have been preset during
configuration to enable one of the characteristics of this function (according to Section
5.1). Furthermore, the teleprotection must be used for the earth fault protection
(address  7HOHSURW () configured to one of the optional methods). If none
of this is the case, this Section 8.3.12.2 is not relevant.
Installation and Commissioning
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