Inspection and diagnostics

Extend the life time of your transformers

The three main factors which can affect the health of the transformers are the paper, which is used for conductor insulation, the pressboard which is used for the major insulation and winding support and the insulating oil.

With age, water and contaminants (air or gas bubbles, particles of different origin, oxygen, and oil ageing) dissolve in the dielectric fluid of the transformer increasing the risk of failures or accelerating ageing of the insulation system, thus reducing the technical life. The level of possible contamination of the insulating oil over the years depends on its design, especially on the effectiveness of the oil preservation system, and sources of contamination.

By sampling and analyzing the dielectric fluid, the presence of contaminants can be detected and appropriate preventative actions initiated. The Oil and Gas Analysis remains a critical component of the condition assessment of the transformer.

Why ABB?

Combining the latest test technology and equipment with a century of design knowledge and expertise, ensures reliable test reports and recommendations

By translating the test data into actionable information and recommendations, an informed decision can be taken on how to tackle the condition of the transformer

Service solutions aimed at addressing problems with the transformer, such as Oil Filtration, Oil Reclamation, Vapour Phase Drying (VPH), are readily available

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Get to know more about oil testing solutions

Scope of work

Methods to assess the quality of the transformer oil:
Dielectric breakdown strength	This test measures the voltage at which the oil electrically breaks down and provides the good indication of the amount of contaminants.
Interfacial tension	This test determines the interfacial tension between the oil sample and distilled water.
Acid neutralization number	This test helps to determine the acid number or acidity of the oil which can be caused by the oxidation process of the insulation forming acids and sludge formation.
Power factor	This test helps to indicate the dielectric loss leakage current of the oil.
Furan analysis	This test helps to understand the paper degradation rate.
PCB content	This test determines the PCB content in the oil and if it meets local environmental regulations.
Corrosive Sulphur CCD test	New test developed to identify oil that may have caused copper sulphide precipitation in cellulosic insulation.
Dissolved Gas Analysis DGA	This test helps to analyze the gasses dissolved in the oil and this test has been used to detect faults or to investigate the cause of the failure.

Using our global reach, we support many customers world-wide in the collection of oil samples, the oil and gas analysis in our certified oil laboratories, as well as providing a first analysis of the units health status. Combining this with our extensive design knowledge as well as repair/refurbishment know-how, accumulated over the years, we can present a more comprehensive report with appropriate recommendations to prolong the usage of the transformer.

Online oil regeneration has technical and economic advantages when applied to old transformers with aged, acidic oil. The process is more environmentally friendly than oil replacement, and demonstrates much better efficiency over the long term. This is a very efficient alternative to passivation, since it enables definitive removal of corrosive compounds from corrosive oils, thus avoiding the risk of copper sulphide formation.

TRAFO-TECH INSPECTION SERVICES

Assessment & Maintenance Plan

Transformers are low maintenance, but not free of maintenance. To determine the maintenance need of your transformer(s), Maintenance Partners offers an assessment that consists of visual inspections, oil sampling, thermography and electrical measurements.

The assessment is the foundation for a maintenance plan in which the condition and priority of each transformer are decisive for the maintenance frequency and needs.

Transformatoren Maintenance Partners - Preventief Onderhoud - StaalnamePreventive Maintenance

For a safe and reliable operation of transformers, preventive maintenance is a must. This detects problems at an early stage and can prevent further deterioration. Preventive maintenance includes the following tests:

Oil sampling + analysis (Oil quality, PCB, furan detection, moist level, …)

Electrical measurements (Insulation resistance, Winding resistance, Transformer Turn Ratios, SFRA-Sweep Frequency Response Analysis, IDAX- Tgδ, …)

In addition, accessories and protections are checked (Detection Gas Pressure Temperature, Buchholz, Thermometer & Fans) and silica gel is replaced.

Maintenance & Repairs Onsite

Transformatoren Maintenance Partners - Onderhoud Onsite 460Besides preventive maintenance, we also execute repairs. The following services are offered onsite:

Dehumidifying, degassing and filtering of oil using steamliner (up to 10.000 l/h)

Refilling or replacing oil

Replacing or repairing of accessories

Renewing of gaskets (all types)

Cleaning of contacts and adjusting torque

Replacing of bushings

Repairing resin / removing corona

Maintenance of tank and conservator: corrosion removal, welding of leaks and repainting

SAT (Site Acceptance Test) + report

Transformatoren Maintenance Partners - Reparaties in Werkplaats 460Maintenance & Repairs in workshop

More comprehensive repairs that cannot be executed onsite are performed in our workshops:

Full electrical test of transformer

Full revision (refurbishment)

Repair of hair cracks and corona traces on cast resin transformers

Repair of HV/LV windings

Repair/renewal of damaged connections

Re-clamping of the winding

Drying of active part

Changing/repairing of tap changers and insulators

Full blasting and painting of reservoir

FAT (Factory Acceptance Test) + report

Engineered Services – Special Projects

Our services on transformers are not limited to maintenance, we also execute Special Projects, such as:

Modifications and Upgrades, (eg. cooling improvement)

Relocations

Installation and Commissioning

Transformatoren Maintenance Partners - IDAX meting 460Testing

Maintenance Partners uses modern testing equipment for complete tests according to the highest standards:

Electrical measurements

Insulation Resistance

Winding Resistance

Transformer Ratios

Transformatoren Maintenance Partners - testen megger 460

Tgδ

SFRA (Sweep Frequency Response Analysis)

Thermography

Oil analyses

Site Acceptance Test after intervention

Factory Acceptance Test after repair

Assessment & Maintenance Plan

Transformers are low maintenance, but not free of maintenance. To determine the maintenance need of your transformer(s), Maintenance Partners offers an assessment that consists of visual inspections, oil sampling, thermography and electrical measurements.

The assessment is the foundation for a maintenance plan in which the condition and priority of each transformer are decisive for the maintenance frequency and needs.

Preventive Maintenance

Oil sampling + analysis (Oil quality, PCB, furan detection, moist level, …)
Electrical measurements (Insulation resistance, Winding resistance, Transformer Turn Ratios, SFRA-Sweep Frequency Response Analysis, IDAX- Tgδ, …)

In addition, accessories and protections are checked (Detection Gas Pressure Temperature, Buchholz, Thermometer & Fans) and silica gel is replaced.

Maintenance & Repairs Onsite

Besides preventive maintenance, we also execute repairs. The following services are offered onsite:

Dehumidifying, degassing and filtering of oil using steamliner (up to 10.000 l/h)
Refilling or replacing oil
Replacing or repairing of accessories
Renewing of gaskets (all types)
Cleaning of contacts and adjusting torque
Replacing of bushings
Repairing resin / removing corona
Maintenance of tank and conservator: corrosion removal, welding of leaks and repainting
SAT (Site Acceptance Test) + report