Regeneration and Strengthening of Oil- immersed Transformersatecco.ir/fa/wp-content/uploads/2016/04/Presentation-MM.pdf · Presentation 02.03.2010, Page 1 MultiMetall the MetalExistenceCompany

Presentation02.03.2010, Page 1MultiMetall the MetalExistenceCompany

Regeneration and Strengthening of Oil-immersed Transformers Horst PenackBerlin, 25 October 2010


Agenda

1. Introduction

2. Overhauling and strengthening

3. Use of PolymerMetal & elastomer

4. Use of Moisture-in-Oil Measurement

5. Concluding discussion

Regeneration and Strengthening of Oil-immersed Type Transformers


Introduction.1

� 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 H2O

� Hermetically sealed transformers and SF6 plants are equally affected

Trafos Reinigung ...


Chapter 2.

2Chapter overview:

1. Introduction


3. PolymerMetal & elastomer

4. Moisture-in-oil measurement

5. Transformer assessment

6. TPM

7. Servicing the active parts of oil-filled transformers

8. Discussion

Overhauling and strengthening.

� Third-party services to be kept between 30–50%

� Repair and maintenance costs to be kept between 3-12% of the plant value

� Plant reliability must be the primary goal of all efforts

� Crash management to be ruled out

� Preventive overhauling and strengthening must be the chief objective


Overhauling and strengthening.2

Classification in categories

Maintenance

Strengthening

Servicing

Inspection

Regeneration(Repair) Renewal

Replacement Partial replacement

Overhauling

Inspection

DIN 31051


Overhauling and strengthening.

Servicing

The sum total of all measures used to preserve and restore the TARGET stateand to determine and assess the ACTUAL state of a s ystem's technical facilities

� Measures to assess and determine

the ACTUAL state of a system's

technical facilities � Measures to be taken:

� Inspection visits including readings

� Measurements

� Checks

Inspection

� Measures to preserve the TARGET state of a system's

technical facilities

� Measures to be taken:� Cleaning

� Flushing

� Conservation

� Lubrication

Maintenance

� Measures to restore the TARGET state of a system‘s technical facilities

� Measures to be taken:� Repair

� Replacement

� Setting

Overhauling

2

Scheduled maintenance:at regular intervals

Condition-basedmaintenance, as needed

Preventiveoverhauling, scheduled

Reactivemaintenance, unexpected



Operation of electrical power installations

Operation ofelectrical power installations

Operation Work

Monitoring Setting Modification CommissioningMaintenance

e.g.

• cleaning

• troubleshooting

• ..

e.g.

• switching

• adjusting

• controlling

* Source: DIN 57105 Part1 / VDE 0105 Part1



Servicing

* Source: DIN 57105 Part1 / VDE 0105 Part1

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



In-house and third-party services



Decision-making support for in-house or third-party aw ard



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


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

2


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


Chapter 3.

Use of PolymerMetal & elastomer

� Leaks in transformers and converters

� Video of applications

3Chapter overview:

1. Introduction



4. Moisture-in-oil measurement

5. Transformer assessment

6. TPM

7. Servicing the active parts of oil-filled transformers

8. Discussion


Chemistry Metallurgy

Resin Hardener Fillers

- Metal powder

- Ceramic powder

Basic material + Hardener = PolymerMetal

Resin + Filler

Use of PolymerMetal & elastomer.3

Manufacture of PolymerMetal



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

� ..



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



Surface preparation

Surface preparation is of vital importance for ensu ring 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

…



Surface preparation (cont'd.)

Surface preparation is of vital importance for ensu ring 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 UWMoist or water-immersed repair surfaces should be degreased and roughened, where

possible.



MM-metal oL-steelceramic

Processing instructionsMixing ratioFor the use of red hardener by volumeMM-metal oL-steelceramic: 2

Red hardener: 1

Auxiliary tool: measur ing 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 volumeMM-metal oL-steelceramic: 8

Yellow hardener: 1

Auxiliary tool: measu ring spoon, yellow

Pot life: 30 minutes at 20°C, congealing time 2.5 h, hardening time 24 h

Application procedureIt is important to adhere precisely to the mixing r atio 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 a dhesion the PolymerMetal must permeate all oil,

grease or gasoline contamination.

Dbl. 200 MM-oL



MM-Basic Set Rs



Sealing with oL

� Insert video


Chemistry Metallurgy

Urethane Hardener Fillers

Oligomeric diamines Polyisocyanate Ceramic powder

Basic material + Hardener = elastomer MM 95

Urethane + Filler


Manufacture of elastomer MM 95



Properties of elastomer MM 95

� Cold processing, prepared on site

� Pot life approx. 11 minutes at 20°C

� High elongation at break: 330%

� High shore hardness A = 95

� Full functional strength achieved after approx. 24 h

� Electric strength approx. 10-13 KV/mm

� Heat resistant in oil up to 120°C

� Available all over the world

� Explain kit with elastomer

Dbl. MM95



Surface preparation and processing of MM95

Surface preparation Create a metallically sound surface through roughening

� Clean the surface by brushing, air-blasting, or vacuum extraction

� Thoroughly degrease the surface with MM solutions as alcohol, gasoline or varnish thinner are unsuitable for this purpose

� If elastomer is applied to a rubber surface it is enough to mechanically roughen and clean the surface

� Thinly coat all surfaces not intended to bond with elastomer with a separating agent and repolish these surfaces after a brief drying period

ProcessingMixing ratio by volumeMM elastomer MM95 : 4

Hardener EL95: 1

Auxiliary tool: Measuring cup

It is important to adhere precisely to the mixing r atio specified.

Mixing must be very intense and thorough.

The material should not be processed at temperature s under +5°C.� Videofilm einblenden



Coating with MM95



Converter heads for 110kV and 220kV



Summary description of how to use oL and MM 95

1. Clean the transformer with a high-pressure washer (e.g. make Kärcher)

2. Locate suspected leaks using e.g. Paris white

3. Removal all paint in the area(s) to be sealed

4. Apply PolymerMetal oL with red hardener to the leak

5. Apply another coating of PolymerMetal oL and yellow hardener

6. After approx. 24 h perform leak checks using e.g. Paris white

7. When treating very big oil leaks be sure to apply vacuum to the transformer during the repair works

8. Repair sites exposed to vibrations or switching operations should be recoated with elastomer after sealing with PolymerMetal



MM SET oL


Chapter 4.

Use of Moisture-in-Oil Measurement

� Online moisture in transformer oil measurement with HMT330

� MM70 moisture meters for random measurements on site

� Measuring kit for load-dependent

moisture-in-oil analysis over an extended period of

time.

4Chapter overview:

1. Introduction



4. Moisture-in- oilmeasurement

5. Transformerassessment

6. TPM

7. Servicing the activeparts of oil-filledtransformers

8. Discussion


Use of Moisture-in-Oil Measurement.4

Moisture-in-oil meter HMT330


Use of Moisture-in-Oil Measurement on Site.4

MM70 Handheld moisture meter


Use of Moisture-in-Oil Measurement.4

Breakdown voltage


Continuation of Chapters 5 -7

Continuation of the seminar by Mr. Georg Daemisch (Chapters 5–8)

Ageing behaviour, determination of remainingsubstance (remaining lifetime) andpreservation of power transformers duringongoing operation

Daemisch Präsentation


Chapter 8.

Concluding discussion

� Q&A and discussion …

8Chapter overview:

1. Introduction



4. Moisture-in-oil measurement on site

5. Discussion


Thank you for your kind attention!

Dipl.-Ing.oec.Ing. Horst Penack

Sewanstr. 16110319 Berlin

Tel. & Fax 030 / 535 62 58Mobile 0172 / 21 10 492

Documents

Regeneration and Strengthening of Oil- immersed Transformersatecco.ir/fa/wp-content/uploads/2016/04/Presentation-MM.pdf · Presentation 02.03.2010, Page 1 MultiMetall the MetalExistenceCompany