Support #550
Incorrect variance adjustment for Time Masters with degradation (loss of GPS)
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:
No
Assigned TF:
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
Updated by Vladan Cvejic about 3 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.
Updated by Carlos Rodriguez del Castillo almost 2 years ago
- Status changed from In Progress to Resolved
- Assignee set to Fred Steinhauser
- Proposal descriptions updated (diff)