Alstom MiCOM P546 - 1.23 Channel aided schemes (Distance option only)

P54x/EN OP/La4 Operation
(OP) 5-58 MiCOM P543, P544, P545 & P546
OP
1.23 Channel aided schemes (Distance option only)
The MiCOM P54x offers two sets of aided channel (“pilot”) schemes, which may be operated
in parallel.
Aided Scheme 1 - May be keyed by distance and/or DEF and/or delta directional
comparison;
Aided Scheme 2 - May be keyed by distance and/or DEF and/or delta directional
comparison;
The provision of two discrete channel selections would allow the following to be
implemented, as an example:
 Distance POR with DEF POR scheme operating over a common shared channel…
Select both in AIDED SCHEME 1 only, with AIDED SCHEME 2 Disabled.
 Distance PUR with DEF BLOCKING operating over separate channels due to the
dissimilar scheme types. Assign Distance to AIDED SCHEME 1, and DEF to AIDED
SCHEME 2.
 Directional Comparison BLOCKING scheme with a second channel for a distance with
DEF BLOCKING scheme operating in unison… Assign Delta to AIDED SCHEME 1, and
both Distance/DEF to AIDED SCHEME 2.
Note: Where schemes share a common channel, the signal send and signal
receive logic operates in a logical “OR” mode.
Aided Scheme 1 and Aided Scheme 2 are two instances of the same logic. Each of these
schemes provides the same options and can be independently applied. The scheme logic is
split into three sections defined in the following diagram: send logic, receive logic, and aided
tripping logic, as shown in Figure 32. Detailed scheme descriptions follow later. As there
are two in
stances of the aided scheme, any internal logic signals which are specific to the
instance of the scheme are shown in the diagrams with two DDB numbers relating to the first
and second instance, respectively.