Alstom MiCOM P546 - 3.6.6 Intermicom64 application example transfer trip; 3.6.7 InterMiCOM64 application example - mapping for two ended application; 3.6.8 Intermicom64 application example - dual redundant communications channels; 3.6.9 Intermicom64 application example - scheme co-ordination timers

P54x/EN AP/La4 Application Notes
(AP) 6-70 MiCOM P543, P544, P545 & P546
AP
3.6.6 Intermicom
64
application example transfer trip
The case study scheme shows a suggested Transfer Trip (“Intertrip”) in the lower dotted box
area. This is an optional addition (or alternative) with any aided scheme. The example
shows an opto input (L5) which is being used to initiate the intertrip, mapped to send IM64 bit
5 to both remote ends. On receipt of the intertrip bit from any remote line end, the OR gate
is used to map the received intertrip to whichever output relay trips the local breaker. In the
diagram, relay 3 is shown as an example.
Again it can be seen that the PSL is the means by which the InterMiCOM
64
signals are
driven, and to where any received bits are routed too.
3.6.7 InterMiCOM
64
application example - mapping for two ended application
The same scheme principle as shown in Figure 26 applies in a two-ended application. The
scheme
will be simplified, whereby Aided Send signals are mapped directly to IM64 bits, on
a one-to-one mapping. The IM64 bit received from the remote end is also mapped directly to
the Aided Scheme Rx signal, requiring no AND or OR logic combination.
3.6.8 Intermicom
64
application example - dual redundant communications channels
In dual redundant operation, the user has the option to send end-end signals via two paths.
The two paths (channels) are defined as Ch1 and Ch2. Several factors can be taken into
account when using this mode:
 The assignment of IM64 bits is completely independent, per channel. For example if all
8 possible bits per channel are assigned to discrete functions, this allows a total of 16
end-end signals.
 The receive logic should employ AND (“both”) or OR (“any”) logic gate functions to
combine the dual redundant signals, as appropriate to the desired operation.
3.6.9 Intermicom
64
application example - scheme co-ordination timers
Distance and DEF and delta directional aided schemes use scheme co-ordination timers to
ensure correct operation. The function of these is documented in the OP sections of the
Technical Manual. However, when using InterMiCOM
64
as the teleprotection channel, the
time delays applied can be different to those used for traditional channels. This is due,
mainly, to the fact that the response time of opto inputs and output contacts is bypassed. An
output contact will take typically 3 to 5 ms to close, and an opto input will take 1 to 2 ms to
recognise a change of state. Therefore, using InterMiCOM
64
will save around 5-6 ms for I/O
response time.
The new time delays appropriate for Dist Dly and Current Reversal Guard timers are as
listed in the following sections. Where direct fiber connections are used for InterMiCOM
64
,
ignore the + MUX addition. Where a multiplexed link is used, the + MUX figure should
account for the multiplexer response time. If this is unknown, it can be obtained for the
specific installation using the appropriate measurement in the MEASUREMENTS 4 menu
column.
3.6.9.1 InterMiCOM
64
application example - distance PUR permissive underreach
 Dist dly = zero
3.6.9.2 InterMiCOM
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application example - distance POR permissive overreach
 Dist dly = zero
 tREV. Guard = 40 ms + MUX