Regeneration and Strengthening of Oil- immersed Transformers Horst - PowerPoint PPT Presentation

Regeneration and Strengthening of Oil- immersed Transformers Horst Penack Berlin, 25 October 2010 Presentation 02.03.2010, Page 1 MultiMetall the MetalExistenceCompany

Agenda Regeneration and Strengthening of Oil- immersed Type Transformers 1. Introduction 2. Overhauling and strengthening 3. Use of PolymerMetal & elastomer 4. Use of Moisture-in-Oil Measurement 5. Concluding discussion Presentation 02.03.2010, Page 2 MultiMetall the MetalExistenceCompany

1 Introduction. � Corrosion = main cause of wear and tear � OH- ions etc. acting as free radicals � Ingress via seals and oil leaks still invisible to the eye � Visible oil leaks indicate that OH- ions have already infiltrated and reacted with the H+ ions to become H 2 O � Hermetically sealed transformers and SF6 plants are equally affected Presentation 02.03.2010, Page 3 MultiMetall the MetalExistenceCompany ��������������������

Chapter 2. 2 Overhauling and strengthening. Chapter overview: � Third-party services to be kept between 30–50% 1. Introduction � 2. Overhauling and Repair and maintenance costs to be kept between 3- strengthening 12% of the plant value 3. PolymerMetal & elastomer � Plant reliability must be the primary goal of all efforts 4. Moisture-in-oil measurement � Crash management to be ruled out 5. Transformer assessment � Preventive overhauling and strengthening must be the 6. TPM 7. Servicing the active chief objective parts of oil-filled transformers 8. Discussion Presentation 02.03.2010, Page 4 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. Classification in categories Strengthening DIN 31051 Servicing Inspection Overhauling Maintenance Inspection Regeneration (Repair) Renewal Replacement Partial replacement Presentation 02.03.2010, Page 5 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. Servicing The sum total of all measures used to preserve and restore the TARGET state and to determine and assess the ACTUAL state of a system's technical facilities Inspection Maintenance Overhauling � Measures to assess and determine � Measures to preserve the � Measures to restore the TARGET state of a system's TARGET state of a system‘s the ACTUAL state of a system's technical facilities technical facilities technical facilities � Measures to be taken: � Measures to be taken: � Measures to be taken: � Repair � Cleaning � Inspection visits including readings � Replacement � Flushing � Measurements � Setting � Conservation � Checks � Lubrication Scheduled maintenance: Preventive at regular intervals overhauling, scheduled Condition-based Reactive maintenance, as needed maintenance, unexpected Presentation 02.03.2010, Page 6 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. Operation of electrical power installations Operation of electrical power installations Operation Work Maintenance Monitoring Setting Modification Commissioning e.g. e.g. • cleaning • switching • troubleshooting • adjusting • controlling • .. * Source: DIN 57105 Part1 / VDE 0105 Part1 Presentation 02.03.2010, Page 7 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. Servicing Servicing comprises works designed to prevent interruptions and/or eliminate defects, to include: � Maintenance, e.g. lubrication or painting � Monitoring, e.g. occasional or regular inspections, measurements, checks � Repair � Replacement of parts � Tests and test runs * Source: DIN 57105 Part1 / VDE 0105 Part1 Presentation 02.03.2010, Page 8 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. In-house and third-party services Presentation 02.03.2010, Page 9 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. Decision-making support for in-house or third-party award Presentation 02.03.2010, Page 10 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening. Overhauling an oil-immersed type transformer � Sealing the transformer � Checking and replenishing the insulating oil � Checking the diverter switch / repairing the on-load tap changer � Repairing motor-drive mechanism � Replacing the signage � Checking the oil conservator vessels � Checking the fan control and bearings � Overhauling the oil pump � Checking the protection and monitoring equipment � Visual checking for corrosion damage � Cleaning � Replacing the standard parts Presentation 02.03.2010, Page 11 MultiMetall the MetalExistenceCompany

2 Overhauling and strengthening Maintenance strategies Condition-based servicing � Definitions for reaching the limit values � Determining the condition based on diagnostics � Use of cost reduction potential Reliability-based servicing � A combination of different strategies � Taking into account all monitoring parameters � Assessment of condition and importance � Determination of failure risk, i.e. preparation of a model for technical and economic evaluation Presentation 02.03.2010, Page 12 MultiMetall the MetalExistenceCompany

Overhauling and strengthening Parameters for determining a transformer‘s condition � Age � Number of switching operations � Operating load, notably power transfer � Noise level � Annual utilization � Revisions and repairs � Measured and visual diagnostic findings � Service and spare part procurement Presentation 02.03.2010, Page 13 MultiMetall the MetalExistenceCompany

Chapter 3. 3 Use of PolymerMetal & elastomer Chapter overview: 1. Introduction 2. Overhauling and strengthening 3. PolymerMetal & elastomer Leaks in transformers and converters � 4. Moisture-in-oil Video of applications measurement � 5. Transformer assessment 6. TPM 7. Servicing the active parts of oil-filled transformers 8. Discussion Presentation 02.03.2010, Page 14 MultiMetall the MetalExistenceCompany

3 Use of PolymerMetal & elastomer. Manufacture of PolymerMetal Chemistry Metallurgy Resin Hardener Fillers - Metal powder - Ceramic powder Basic material + Hardener = PolymerMetal Resin + Filler Presentation 02.03.2010, Page 15 MultiMetall the MetalExistenceCompany

3 Use of PolymerMetal & elastomer. Properties of PolymerMetal � Cold processing, produced on site � Pot life between 2 minutes….60 minutes � No fire – no explosion risk � Thixotropic, i.e. “no expiry“ � Very low shrinkage � Mechanical processing possible after approx. 3 hours � Full functional strength achieved after approx. 24 hours � Supports any type of mechanical processing � Hardens even in sub-zero temperatures � .. Presentation 02.03.2010, Page 16 MultiMetall the MetalExistenceCompany

3 Use of PolymerMetal & elastomer. Properties of PolymerMetal (cont‘d.) � No rust formation underneath the coating, high resistance to chemicals � Outstanding corrosion protection � No stress cracking from heat � Repairs possible without need of disassembling components � Shelf life approx. 5-10 years at approx. 20° C � Significant reduction of repair times � Significant reduction of repair costs � Available all over the world Presentation 02.03.2010, Page 17 MultiMetall the MetalExistenceCompany

3 Use of PolymerMetal & elastomer. Surface preparation Surface preparation is of vital importance for ensuring optimum success of the repair measures A: For normal PolymerMetals 1. Create a metallically clean and sound surface 2. Roughen the surface mechanically through particle-blasting, machining, grinding, etc. 3. Reclean the surface by brushing, air-blasting, or vacuum extraction 4. Thoroughly degrease the surface with special solutions … Presentation 02.03.2010, Page 18 MultiMetall the MetalExistenceCompany

3 Use of PolymerMetal & elastomer. Surface preparation (cont'd.) Surface preparation is of vital importance for ensuring optimum success of the repair measures B: For MM-metal oL-steelceramic 1. Create a sound surface 2. Always remove any paint, surface should be roughened where possible 3. Grinding residue is not a problem 4. Reduce the oil flow for economical reasons C: For MM-metal UW Moist or water-immersed repair surfaces should be degreased and roughened, where possible. Presentation 02.03.2010, Page 19 MultiMetall the MetalExistenceCompany

3 Use of PolymerMetal & elastomer. MM-metal oL-steelceramic Processing instructions Mixing ratio For the use of red hardener by volume MM-metal oL-steelceramic: 2 Red hardener: 1 Auxiliary tool: measuring spoon, red Pot life: 4 minutes at 20° C, congealing time 20 min utes, hardening time 45 minutes For the use of yellow hardener by volume MM-metal oL-steelceramic: 8 Yellow hardener: 1 Auxiliary tool: measuring spoon, yellow Pot life: 30 minutes at 20° C, congealing time 2.5 h, hardening time 24 h Application procedure It is important to adhere precisely to the mixing ratio specified for MM-metal oL to red or yellow hardener. Mixing must be very intense and thorough. Compact volumes should be avoided to ensure compliance with the specified pot times. For good adhesion the PolymerMetal must permeate all oil, grease or gasoline contamination. Presentation 02.03.2010, Page 20 �������������� MultiMetall the MetalExistenceCompany