Power Transformers

• Technical specifications

  A specification that says what the machine must do and how it will be proven: ratings, impedances, losses, insulation levels, short-circuit withstand, cooling, sound, tests. Written for the buyer, so that offers are comparable and the test report can be checked line by line.

  

• Design review and design from scratch

  Review of the manufacturer’s electrical, dielectric, short-circuit, thermal and mechanical design before production, with our own calculation as the benchmark. When needed, the complete design from scratch with our Power Transformers Design program. Design reviews carried out on 230 kV to 500 kV units and on HVDC converter transformers.

  

• Testing, factory and field

  Witnessing of routine, type and special tests in the factory, including dynamic short-circuit tests, and of site tests after installation. Every measurement is compared with the guaranteed values and with the design.

  

• Diagnostics and maintenance

  Condition assessment of transformers in service: oil sampling, dissolved-gas analysis, furans, electrical measurements, inspection of the active part. Diagnostic plans for whole fleets, supported by our Oil Analysis & Maintenance program.

  

• Failure analysis

  Root-cause analysis after a failure in test or in service: inspection of the active part, reading of the test and gas records, reconstruction of the event, and a report that holds up with the manufacturer, the insurer and, if needed, in court.

  

• Remaining life

  Estimate of the residual life of a unit or a fleet from the oil-analysis history, the loading and the maintenance records, to decide between life extension, refurbishment and replacement.

  

The quality chain of a procurement, step by step.

1. 1

   Specification

   Ratings, guarantees and test programme written before the tender.

2. 2

   Design review

   The manufacturer’s design checked against our own calculation before production.

3. 3

   Manufacturing inspections

   Core, windings, active part and tank inspected at the right moments in the factory.

4. 4

   Acceptance tests

   Factory and site tests witnessed, report checked line by line.

5. 5

   Service life

   Diagnostics, life extension and, if it comes to that, failure analysis.

1. Italy, 2018

   Quality Assurance in a Power Transformer Procurement

   Position

   Power Transformers expert

   Duties

   Quality Assurance in the procurement of a 240 MVA 400 kV step-up power transformer, including: a) technical specification; b) design review; c) manufacturing inspections; d) acceptance test inspection.

2. China, 2017

   Design Review of four power transformers

   Position

   Transformer design expert

   Duties

   Design Review of four HV (500 kV) power transformers.

3. Germany, 2016

   Design Review of power transformer

   Position

   Transformer design expert

   Duties

   HVDC 400 kV AC / 500 kV DC power-transformer design review.

4. Italy, 2018

   Power Transformers Life Extension

   Position

   Power Transformer Diagnostic and Maintenance expert

   Duties

   For a population of 60 power transformers in 6 power plants, including 400 kV step-up transformers and HV / MV transformers, residual life and condition of the population were established to evaluate a possible 10-year life extension. To automate the process, a database of the available oil-analysis history was created.

5. Dominican Republic, 2015

   Failure analysis of a power transformer in CCP of Santo Domingo

   Position

   Transformer design expert

   Duties

   Failure analysis of a power-transformer explosion. Live testimony in the Dominican Republic Court of Justice.

6. Perú, 2019

   Power Transformer Active Part Inspection

   Position

   Transformer Expert

   Duties

   Active part inspection on a faulted transformer.