1748   Arrays of CDC

Created: 20 Jan 2021

Status: Future Improvement

Part: Part 7-4 (2020; Edition 2.1)

Links:

Page: 282

Clause: 12.13.8

Paragraph: FltDiskm

Issue

Some fault location algorithms for tapped lines return several possible places(the amount is changed from one case to another) where a fault could be. As far as RFLO.FltDiskm belongs to CDC MV it is not possible to wrap such family of algorithms by LN RFLO due to the impossibility to define the array of float values according to IEC61850 rules. It is impossible to solve it even by adding custom DO because no suitable CDCs, and custom CDCs are prohibited.
An ideal solution would be a possibility to define arrays of standard CDC, but there is no such option now.
Existing HMV CDC(single CDC in measurement group that somehow allows to model array of float values) contains some mandatory attributes as Frequency, numCyc and so on, that makes no sense here.

Proposal

I would propose several options to address that issue:
1. Adding the way to define arrays of standard CDC
2. Defining the standard CDC that contains an array of float values.
3. Setting presence condition for RFLO.FltDiskm to Omulti