Life Time Management of Power Transformer

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Life Time Management of Power Transformer

• C. Sumereder, M. Muhr, B. Körbler
• Graz University of Technology
• Dep. High Voltage Engineering

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Agenda

• Age and aging mechanism of paper/oil insulating
  systems
• Condition evaluation dued to age and maintenance
• Maintenance strategies / risk
• Technical Diagnosis

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Age and Aging Mechanism

• in general Law of Arrenhius
• Paper/Oil Insulation System Montsinger

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Condition Formula

• CAGE age condition factor
• LT expected useful lifetime
• AGE age
• A,b,c constants

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Maintenance Strategies

• TBM Time Based Maintenance Measures were done
  in regular intervals
• Since electricity market is liberalized
• CBM Condition Based Maintenance Monitoring of
  the network components is essential, monitoring
  parameters have to be defined diagnosis level

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Maintenance Parameters / Risk

• Failure Statistics
• Determination of Repair Costs
• Repair Time and Procedure
• Evaluation of Interrupt Costs
• Philosophy of Company
• Risk Watch Diagnosis and Critical Level

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Technical Diagnosis

• Chemical Diagnostics
• Oil Analysis (IEC 60422)
• Dissolved and free gasses (IIEC 60567)
• Dissolved Furans (IEC 61198)
• Electrical Diagnostics
• Partial Discharge Measurement (IEC 60270)
• Thermal Diagnostics

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Summary

• Maintenance Strategy Philosophy of utility and
  producer
• Mechanism of Aging Degradation of paper/oil
  System
• Condition Evaluation Technical Diagnosis
• Experience of engineers