Project

General

Profile

Support #550

Incorrect variance adjustment for Time Masters with degradation (loss of GPS)

Added by Herbert Falk almost 2 years ago. Updated 5 months ago.

Status:
Resolved
Priority:
Normal
Category:
Standard clarification required
Start date:
Due date:
% Done:

0%

Estimated time:
ID:
31
Source:
IOP_2017/52
TF Unique ID:
31 # IOP_2017/52
WG10 Proposal:
Estimated Completion:
Discuss in Upcoming Meeting:
No
To discuss in WG10:
Short Proposal:

To send to Hubert for next 9-3 revision

Standard(s):

IEC 61850-9-3

Needs More Information:

Description

All masters adjust correctly (and conservatively) the ClockAccuracy field when degrading (loss of GPS) but they do not adjust the variance (offsetScaledLogVariance) correctly. This is a measured value that is used in the Best Master selection. Most clocks set the variance to 0 or 65535, or to a fixed (not computed) value.
Therefore, this field is unusable in the BMCA, a clock with a very poor variance could win over another clock that claims 0 variance.
IEC/IEEE 61850-9-3 should indicate specifically that the variance has to be adjusted.


Proposal descriptions

Assigned to IEC 61850-9-3

#1

Updated by Vladan Cvejic almost 2 years ago

  • Subject changed from All masters adjust correctly (and conservatively) the ClockAccuracy field when degrading (loss of GPS) but they do not adjust th to Incorrect variance adjustment for Time Masters with degradation (loss of GPS)
  • Category set to Standard clarification required
  • Status changed from New to In Progress
  • Standard(s) changed from 3-Sep to IEC 61850-9-3
  • Discuss in Upcoming Meeting set to No

Checking done.

#2

Updated by Carlos Rodriguez del Castillo 5 months ago

  • Status changed from In Progress to Resolved
  • Assignee set to Fred Steinhauser
  • Proposal descriptions updated (diff)

Also available in: Atom PDF