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2. Overview of PaperHistory of DFR applications at Southern California Edison (SCE)Requirements for New Technology DFRsIdentify need to replace First Generation DFRsSample Event Recordings Staffing needs for DFR replacement program. 3. History of DFRs at SCEBefore 1980's -
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1. 1 2003 Georgia TechFault & Disturbance Analysis Conference Upgrading DFR Systemsby Robert Baldwin
Southern California Edison
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Overview of Paper
History of DFR applications at Southern California Edison (SCE)
Requirements for New Technology DFRs
Identify need to replace First Generation DFRs
Sample Event Recordings
Staffing needs for DFR replacement program
3. 3 History of DFRs at SCE
Before 1980’s -- magnetic drum, ink-type, and light beam oscillographs at SCE
1985 to 1990 -- SCE replaces its early fault recording systems with first generation DFRs
2001 -- SCE begins a ten-year program to replace its first generation DFRs with newer technology DFRs
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First Generation DFRs at SCE
Event storage capability at remote DFR
Modem communications used for retrieval of event records from remotely located DFRs
Printed event records very similar to those provided by early fault recorders
Event analysis tools available at DFR Master Station computer (ex. Sequence components)
5. 5 Some Limitations of First
Generation DFRs Applied at SCE
Static RAM storage of events at DFR
No Hard Disk Units (HDUs) at DFR
Communications to remote DFR by modem, only
Event records available for printing and analysis at DFR Master Station computer, only
6. 6 Requirements for new technology
DFRs to be applied at SCE
Industry-recognized leader in the development of highly reliable DFR systems
“Open access” to DFRs (no single DFR Master Station required)
Ethernet communication available
Reliable high-speed modem communications
Multiple recording speeds within same DFR
Long-Term event storage technology
7. 7 Requirements for new technology
DFRs to be applied at SCE (cont’d)
Extensive, yet simple to use DFR Analysis software
Integrated database for management of event recordings
Auto-export records in Comtrade format
Import Comtrade records
Sequence-of-Event (SOE) view
Selectable event recording initiation from all analog and digital input channels
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Need to Replace First Generation
DFRs at SCE
DFRs considered to be a necessity
Transformer failure events
Non-volatile storage of event data
Increase reliability of communications to DFRs
Record database capability
Open the access to DFR event recordings
Ethernet communications to remote DFRs
Sequence of event record viewing
9. 9 SCE Considers DFRs Necessary
Reduced staffing in 1990’s
More work with less people
Loss of key personnel
Knowledge of past practices
Measure system performance
Relays, circuit breakers, etc.
10. 10 Transformer Failure Events at
Stations with First Generation DFRs
Two major power transformer failures
Resulting oil fire at both substations
Damage to each station’s control cables
DFRs recorded initial event
DFRs limited static RAM storage of resulted in no event records after a few seconds
Lost event data due to loss of station DC system
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12. 12 Transformer Failure Event at Station with New Technology DFR
Major power transformer failure
Resulting oil fire at substation
Damage to station’s control cables
DFR recorded all event data
DFR’s Hard Disk Unit (HDU) stored all event data, allowing access to event records when station’s DC system was restored
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Non-Volatile Storage of Event Data
August 10, 1996 WSCC System Disturbance
Event lasted well over a minute’s time
First generation DFR’s static RAM were filled to capacity and then stopped recording
Limited data captured at station DFRs
Much of the event data was lost
14. 14 Non-Volatile Storage
of Event Data (cont’d)
Availability of HDU in new technology DFR
HDU offers immediate storage of event data at DFR, allowing DFR’s static RAM to continue recording in real-time
HDU continues to store event data during DFR communication outages
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16. 16 Increased Reliability of
Communications to DFRs
Modem initialization problems with first generation DFRs
Troubleshooting communication outages related to the DFR’s modem line
New technology DFRs offer logging features
Date and time stamp
Type of error at DFR
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Record Database Capabilities
Older records retrieved from first generation DFRs
Limited search capabilities in first generation Master Station software
New technology DFRs offer built-in database search engines
Date and time
Event type
Size of event record
Etc.
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Access to DFR Event Recordings
Limited access to first generation DFRs
New technology DFRs allow many users access to event recording data
Event data more readily available to people making system restoration decisions
Grid Dispatch & Operations
Protection Staff
Apparatus Staff
Etc.
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Ethernet Communications to DFRs
Reduce time spent with DFRs
Retrieval of event recordings
Revise DFR’s trigger/sensor parameters
Revise channel parameters
22. 22 Sequence of Event (SOE)
Viewing of Event Recordings
Extracting data from past system events captured by first generation DFRs very tedious task
New technology DFRs offer SOE view of event data
Time stamp
Normal/abnormal indication
Channel initiation
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Sample Event Recordings
Transient record (6000 Hz sampling rate)
Slow-Speed record (60 Hz sampling rate)
Continuous record (20 Hz sampling rate)
Use of Calculated Channel
Negative sequence overvoltage trigger/sensor
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Staffing Considerations
Items to be Addressed
Channel count (analogs and/or digitals)
Retro-fit or complete replacement
Station electrical drawing revisions
Power system quantities of interest
Acceptable trigger/sensor levels
Maximum recording time intervals
Coordination of project to replace first generation DFRs
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Staffing Considerations (cont’d)
Senior Team Players
Lead Protection Engineer
Area Protection Engineer
Information Technology Engineer
Technical Specialist
Design Engineer
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Summary
Reduced time spent in tasks with DFR
Open access to event recordings
Ethernet has increased reliability of communications to remote DFR
Hard Disk Unit minimizes possibility of lost event recordings at DFR
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