P54x/EN CM/La4 Commissioning
(CM) 10-54
MiCOM P543, P544, P545 & P546
CM
8.4.11 DEF aided scheme - scheme testing
8.4.11.1 Signal send test for permissive schemes (POR/POTT only)
Firstly, recon
nect the test set so that the timer is no longer stopped by the Trip contact, but is
now stopped by the Signal Send contact (the contact that would normally be connected to
the pilot/signaling channel).
Repeat the forward
fault injection, and record the signal send contact operating time. The
measured operating time should typically be less than 40ms. Switch OFF the ac supply and
reset the alarms.
8.4.11.2 Signal send test for blocking schemes only
Firstly, recon
nect the test set so that the timer is no longer stopped by the Trip contact, but is
now stopped by the Signal Send contact (the contact that would normally be connected to
the pilot/signaling channel).
Secondly, reverse the current flow direction on the A phase, to simulate a reverse
fault.
Perform the reverse fault injection, and record the signal send contact operating time. The
measured operating time should typically be less than 40 ms. Switch OFF the ac supply and
reset the alarms.
Upon completion of the tests any phase diff, distance, overcurrent, earth fault, breaker
fail or supervision elements which were disabled for testing purposes must have their
original settings restored in the CONFIGURATION column. Ensure that any
wires/leads temporarily fitted to energize the channel receive opto input have been
removed.
8.4.12 Backup phase overcurrent protection
If the overcurrent p
rotection function is being used, the >1 element should be tested. If not,
skip to section 8.4.13.
Refer to section 8.4.1, check for any possible dependen
cy conditions and simulate as
appropriate.
To avoid spurious operation of any distance, DEF, earth fault or breaker fail elements, these
should be disabled for the duration of the overcurrent tests. This is done in the relay’s
CONFIGURATION column. If the overcurrent element is enabled without qualification of
communication channel failure, then the current differential element [090F: Phase Diff],
should be disabled. If the overcurrent protection is enabled on communication channel
failure, then the differential element should remain enabled and the communication should
be disrupted to cause a suitable failure of the phase differential protection. Make a note of
which elements need to be re-enabled after testing.
8.4.12.1 Connect the test circuit
Determine
which output relay has been selected to operate when an >1 trip occurs by
viewing the relay’s programmable scheme logic.
The relay assigned for Trip Output A (DDB 523) faults should be used.
Stage 1 should be mapped directly to an output relay in the programmable scheme logic. If
default PSL is used, Relay 3 can be used as I1> is mapped to Trip inputs 3 Ph (DDB 529)
that in turn is internally mapped to Any Trip (DDB 522) mapped to relay 3 (see trip
conversion logic on chapter P54x/EN OP) .
Connect the output relay so that its operation will trip the test set and stop the timer.
Connect the current output of the test set to the ‘A’ phase current transformer input of the
relay (terminals C3 and C2 where 1A current transformers are being used and terminals C1
and C2 for 5A current transformers).
If [3503: GROUP 1 OVERCURRENT, >1 Directional] is set to ‘Directional Fwd’, the current
should flow out of terminal C2 but into C2 if set to ‘Directional Rev’.
To Next Page
Loading...
