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![Review – Offline Transformer Diagnostic Testing
Polarisation Index
IEEE Std 62-1995 Paragraph 6.1.5
IEC 60076-1 (2000), clause 10.1.3
Turns Ratio
IEEE Std 62-1995 Paragraph 6.1.2
IEC 60076-1 (2000), clause 6
turns ratio tolerance should be within 0.5% of the
rating plate specifications for all windings
Winding Resistance
IEEE Std 62-1995 Paragraph 6.1.1
IEC 60076-1 (2000), clause 10.2
winding resistance within 5% tolerance compared to
the rating plate and previous results
Insulation Power Factor/ Tan Delta
IEEE- std 62-1995
IEEE std 57.12.90-1999 clause 10.10 [51]
IEC 60076-1 (2000) clause 10.1.3
Additional tests include but not limited to
• Dirana
• SFRA
PI Condition
<1 Dangerous
1 - 1.1 Poor
1.1 – 1.25 Questionable
1.25 - 2 Fair
>2 2.0 Good
Transformer
Condition of Insulation
Good Maybe
Acceptable
Should be
investigated
New DF < 0.5% - -
Serviced-aged DF < 0.5% 0.5% < DF < 1% Df > 1%
All values measured at 20°C](https://image.slidesharecdn.com/7542645d-64c2-4fbc-b747-ae5188155f51-151222072939/85/Asset-Management-Presentation-13-320.jpg)
Uploaded byMichael Meehan MIEAust
Asset Management Presentation
This document discusses asset management and maintenance delivery, focusing on predictive maintenance through diagnostic testing of electrical assets. It provides an overview of asset management principles and decision making, then details various online and offline diagnostic tests for transformers, switchyards, motors, switchgear, and cables. These include tests like oil analysis, thermography, partial discharge testing, and insulation resistance measurements. Condition criteria are outlined to assess asset health and determine maintenance needs based on test results. Consistency in test setup and documentation is emphasized for effective trend analysis.
Asset Management Presentation
- 1. Asset Management Maintenance Delivery- Diagnostic Testing Electrical Assets
- 2. Agenda • What isAsset Management • Asset Management Decision Making • Maintenance Delivery • PdM – Diagnostic Testing
- 3. ISO 55000:2014 AssetManagement Definition hghhhh “The coordinated activity of an organization to realise value from assets”
- 4. Asset Management SystemElements
- 5.
- 6. 39 Subjects ofAsset Management by IAM
- 7. Asset Management DecisionMaking • Capital Investment Decision Making • Operation & Maintenance Decision Making • Life Cycle Value Realisation • Resourcing Strategy & Optimisation • Resourcing Strategy • Shutdowns & Outage Strategy
- 8. Condition Assessment Criteria `whatis the condition of the asset` OR `When will the condition of the asset become unacceptable`
- 9. Operation & MaintenanceDecision Making • Maintenance regimes must provide value to the organisation to be justified Tools to define optimum maintenance frequencies • FMEA – Failure Mode and effects Analysis • RCM – Reliability Centred Maintenance • RBI – Risk Based Inspection – optimise Where companies have adopted manufacturers maintenance regimes they must look to justify maintenance schedules. Are labour and resources used efficiently?
- 10. Maintenance Delivery Preventive PM– Often manufacturer recommended PM frequencies, functional system checks (SIL), Haz Area Predictive PdM – Equipment diagnostic testing techniques Condition Monitoring CM – Machines(PROGNOST®/Bentley Nevada) – Online PD Corrective - Repair or adjustment for a condition detected in PM/PdM Emergency – Breakdowns equipment failures
- 11. PdM - PrimaryElectrical Assets • Transformers • Motors • Switchgear/Switchyards • HV Cables
- 12. PdM - TransformerDiagnostic Testing Online • Oil Analysis – DGA – Furans • Infrared Thermography • Acoustic Emissions (AE) • UHF Partial Discharge • Radio Frequency Interference (RFI) Note: - The test methods listed are not the only test that can be performed, this list is made up of common tests requested by customers. Offline • Insulation Resistance • Power Factor/DDF • DC Winding Resistance • Turns Ratio • Leakage Impedance • SFRA • Dirana
- 13. Review – OfflineTransformer Diagnostic Testing Polarisation Index IEEE Std 62-1995 Paragraph 6.1.5 IEC 60076-1 (2000), clause 10.1.3 Turns Ratio IEEE Std 62-1995 Paragraph 6.1.2 IEC 60076-1 (2000), clause 6 turns ratio tolerance should be within 0.5% of the rating plate specifications for all windings Winding Resistance IEEE Std 62-1995 Paragraph 6.1.1 IEC 60076-1 (2000), clause 10.2 winding resistance within 5% tolerance compared to the rating plate and previous results Insulation Power Factor/ Tan Delta IEEE- std 62-1995 IEEE std 57.12.90-1999 clause 10.10 [51] IEC 60076-1 (2000) clause 10.1.3 Additional tests include but not limited to • Dirana • SFRA PI Condition <1 Dangerous 1 - 1.1 Poor 1.1 – 1.25 Questionable 1.25 - 2 Fair >2 2.0 Good Transformer Condition of Insulation Good Maybe Acceptable Should be investigated New DF < 0.5% - - Serviced-aged DF < 0.5% 0.5% < DF < 1% Df > 1% All values measured at 20°C
- 14. Review – OnlineTransformer Diagnostic Testing Condition DGA Good Acceptable Questionable Unacceptable Hydrogen (H2) < 100 ppm 101 to 700 ppm 701 to 1,800 ppm > 1,800 ppm Methane (CH4) >120 ppm 121 to 400 ppm 401 to 1,000 ppm > 1,000 ppm Ethane (C2H6) < 65 ppm 66 to 100 ppm 101 to 150 ppm > 150 ppm Ethylene (C2H4) < 50 ppm 51 to 100 ppm 101 to 200 ppm > 200 ppm Acetylene (C2H2) < 35 ppm 36 to 50 ppm 51 to 80 ppm > 80 ppm Carbon Monoxide (CO) < 350 ppm 351 to 570 ppm 571 to 1,400 ppm > 1,400 ppm Carbon Dioxide (C02) < 2,500 ppm 2,500 to 4,000 ppm 401 to 10,000 ppm > 10,000 ppm Oxygen (O2) <0. 2 % 0.2 – 3.5 % > 3.5 % NFG Nitrogen (N2) < 1 % 1 - 10 % > 10 % NFG TDCG < 720 ppm 721 – 1,920 ppm 1,921 – 4,630 ppm > 4,630 ppm Insulation Fluid Analysis (IFA) Moisture – 220/132 kV < 5 ppm 5 to 15 ppm 15 to 25 ppm > 25 ppm Moisture – 33 kV + MV < 10 ppm 10 to 25 ppm 25 to 30ppm > 30 ppm Moisture % - M/DW < 0.5 M/dw 0.5 to 1.5 % M/dw 3.3-6% M/dw > 7% M/dw Dielectric Breakdown (BV) – 220/132 kV > 50 kV 40 to 50 kV 30 to 40 kV < 30 kV Dielectric Breakdown (BV) – 33 kV > 40 kV 30 to 40 kV 20 to 30 kV < 30 kV Dielectric Dissipation/ Factor (PF) < 0.5 % 0.5 % to 1.0% 0.5 % to 1.0% Inc > 1.0 % IFT - Interfacial Tension > 32 dynes/cm 28 - 32 dynes /cm 22 < 28 dynes /cm < 22 dynes/cm Acidity No. – ASTM D-974 < 0.03 mgKOH/g > 0.03 < 0.05 mgKOH/g > 0.05 < 0.20 mgKOH/g > 0.20 mgKOH/g Furans 0.01 ppm 0.1 ppm 1.00 ppm > 5 ppm Condition DP Furaldehyde Content (ppm) Good 717 - 1003 0.01 Moderate Deterioration 431 - 717 0.1 Extensive Deterioration 232 - 431 1 End of Life < 232 >5 DP - Degree of Polymerisation
- 15. Review – OnlineTransformer Diagnostic Testing
- 16. PdM - SwitchyardDiagnostic Testing Bushings - CTs – VTs – Circuit Breakers • Insulation Resistance • DDF • Thermography • PD • Corona • Oil Analysis
- 17. Review – SwitchyardDiagnostic Testing Corona Camera RFI - Radio Frequency Interference (RFI)
- 18. Review – SwitchyardDiagnostic Testing Bushing Test Capacitance C2 Power & Dissipation Factor Good <0.5% - Monitor >0.5% < 1.0% & 5% variation from nameplate Between nameplate power factor & up to twice nameplate power factor Poor >0.5% < 1.0% & 10% variation from nameplate Between twice nameplate power factor & up to 3 times nameplate power factor Replace > 1.0% and increasing > 10% of nameplate Above 3 times nameplate power factor
- 19. PdM – MotorInsulation Diagnostic Testing Offline • DC Insulation Resistance – PI • DLA/DDF • Partial Discharge (PD) • ElCid • RSO • Note: - The test methods listed are not the only test that can be performed, this list is made up of common tests requested by customers. Online • Partial Discharge
- 20. Review – MotorInsulation Diagnostic Testing DC Insulation Resistance Insulation Power Factor DDF/ Tan Delta DDF testing proves more beneficial when trending(monitoring change) PI Condition <1 Poor 1-2 Questionable 2-4 Fair >4 Good Insulation System %PF@2kV %PF Tip-Up Asphalt-Mica 3.0 or less 2.0 or less Polyester & Epoxy Mica 1.0 or less 1.0 or less Pre-1980 Epoxy Mica 1.5 or less 1.5or less
- 21. Review – MotorInsulation Diagnostic Testing Partial Discharge Base lining and continues trending provides best value from PD testing. ElCiD – Electromagnetic Core imperfection Detection
- 22. PdM – SwitchgearCondition Monitoring Online • Partial Discharge Offline • Partial Discharge • Insulation Resistance • Circuit Breakers M`tce
- 23. Review – SwitchgearDiagnostic Testing Circuit Breaker • Contact speed/motion measurement • Close over travel measurement • Close damping measurement • Trip damping measurement • Arcing contact timing • Dynamic resistance measurement (DRM) • Oil Sampling • Motor-mechanism checks, function check safety devices etc.
- 24. PdM – SwitchgearDiagnostic Testing Partial Discharge Survey
- 25. PdM – HVCable Diagnostic Testing Offline • Partial Discharge Mapping (OWTS) • VLF • Tan Delta Online • Partial Discharge
- 26. PdM – HVCable Diagnostic Testing DLA Testing (Tan Delta)
- 27. PdM – HVCable Diagnostic Testing
- 28. Consistency in DiagnosticTesting Techniques It is critical that test conditions are recorded when testing to enable trending • Temperature • Humidity • Load • Test equipment • Type Model • Test voltage/current • Connection arrangements
- 29.