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DGA Oncors Past, Present, and Future Dustin Best Russell W. Smith - - PowerPoint PPT Presentation
DGA Oncors Past, Present, and Future Dustin Best Russell W. Smith - - PowerPoint PPT Presentation
DGA Oncors Past, Present, and Future Dustin Best Russell W. Smith Hannah Webb SEPTEMBER 5 - 7, 2018 SEPTEMBER 5 - 7, 2018 Oncor Transformer Fleet Approximate Approximate Number of Number of DGA's Annually (not Transformer
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Oncor Transformer Fleet
Transformer Approximate Number of Transformers Approximate Number of DGA's Annually (not including resamples) 3 Phase with LTC 1,232 2,464 3 Phase without LTC 718 718 1 Phase Substations 75 Total 2,025 3,182
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1980’s
- Early 1980’s
– Time-based maintenance on every LTC yearly and eventually moved to every 3 years.
- Very Labor Intensive
- Mid-Late 1980’s
– Dissolved Gas Analysis (DGA) began on main tanks.
- Focus: Acetylene, Moisture Content, and Total
Combustible Gas
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1990’s
- Early-Mid 1990’s
– Time-based maintenance on every LTC moved to every 6 years or after 30,000 operations .
- Unknown condition between the 6 years.
- Late 1990’s
– Oncor committee formed to focus on the development of analyzing LTC DGAs.
- Research cause of coking.
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2000’s
- Early 2000’s
– Committee began experimenting with arcing in oil and reviewing the gas relationships.
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2000’s
- Mid 2000’s
– Transition to automated DGA email notifications.
- Reporting system used algorithms developed by the
committee to determine the condition of the asset.
- Levels of Concern: caution, warning, wet, etc.
- Notifications sent to specific lists of personnel.
- Late 2000’s
– Single and Multi-gas online monitors evaluated for selected autotransformer main tanks.
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2010’s
- Early 2010’s
– Transition to a centralized asset data base with reporting capabilities.
- Same algorithms utilized
- Better organization and tracking
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2010’s
- Mid 2010’s
– Refinement of DGA notification algorithms on both main tanks and LTCs. – Single gas online monitors were specified to come on all new medium power transformers on both main tank and vacuum LTC.
DGA Notification Refinements Refinement Before After Reduced by Moisture tracking 695 154 541 LTC 802 222 580 Total 1497 376 1121
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2010’s
- Late 2010’s
– Basic DGA trending dashboard – Notifications setup for online monitors – Further refinement on DGA notifications
- LTC model specific
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Beyond
- Advanced DGA Fleet Dashboard
– Arrange assets in order of highest concern
- Asset Health Score
– Prioritize maintenance and/or proactive replacements based on score
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