Tests of transformers and electrical insulation

Obiekt badań

Activity of the Transformers and insulation test Team includes all works associated with this issue, in particular:

  • post assembly, routine and after breakdown measurements of transformers,
  • comprehensive transformer diagnostic tests enabling:
    • evaluation of the technical condition of transformers helpful at making a decision on their further use or the necessity of repair and maintenance works,
    • determination of the degree of transformer's insulation wear and the time of further operation,
    • execution of transformer insulation treatment extending insulation life as well as use of the optimal technology of insulation treatment and insulation quality inspection,
  • supervision of transformers production, repair and modernization works (to represent a client interest at the factory of transformers, at the transformer repair plants and at insurance companies),
  • diagnostic in "on-line" and "off-line" systems,
  • supervision of maintenance and repair works at the transformer installation place,
  • elimination of hazards caused of the presence of corrosion sulfur in oil.

Long-term research works and experience acquired in the field of transformers technical diagnostics enabled to develop new methods, which brought into wide applying demonstrated the great usefulness.

Laboratorium diagnostyczne Zespołu Diagnostyki Transformatorów







Following topics deserve particular attention:

  • diagnostics of transformer internal failures on the basis of chromatographic analysis of gasses dissolved in oil, enabling:
    • detection and identification of hidden defects in transformers,
    • observation of the development of damage in the time function,
    • determination of the moment of the transformer switch off (appropriately early taking preventive measures) according to own evaluation criteria, adapted for domestic transformers,
  • additional diagnostic investigation enabling the exact location of damage in transformers, such as:
    • vibroacoustic examination enabling the evaluation of the state of transformer's core,
    • partial discharge test,
    • insulation tests based on polarizing methods,
  • diagnostics of on-load tap changers enabling on the installation position of the transformer (without disassembly of the head) evaluation of the technical condition of the tap changer; the method also allows for the evaluation of selectors of the transformer,
  • diagnostics of the mechanical condition of windings with SFRA method. The tests are carried out with the specialist apparatus of the Double company – USA.

Experience acquired, as well as the results of research works from this period are applied among other things to:

  • assess the ageing ratio of transformer's insulation,
  • assess the degree of moisture of transformer's insulation,
  • determine the scope and the profitability of the repair,
  • determine transformers life expectancy.

In the scope of transformer oil tests we carry out:

  • tests and measurements of new oils, also during the assembly and oil processing on the transformer's installation position,
  • tests of oil of transformers in operation,
  • special examinations concerning technology of processing, possibility of mixing different oils up, determining the ageing reasons, needs for the exchange of oil,
  • oils ageing tests,
  • drawing up the technology of the regeneration of oil,
  • trainings and consultation in maintenance and diagnostics of transformers,
  • assessments of the degree of using of oil based on own criteria.

Because the considerable part of domestic power transformers exceeded the 25-year operating period, to the purpose of extension of the period of their further failure-free operation, for transformers with the long-standing period of operation, comprehensive tests of insulation parameter indicators, insulating materials and the degree of moisture of the transformer's isolation were conducted.
Obtained tests results served for development of methods of insulation treatment enabling to extend the lifetime of these transformers.



All questions should be directed to:

  • Waldemar Olech MSc Eng., , phone number: +48 32 237 66 23,
  • Halina Olejniczak Eng., , phone number: +48 32 237 66 28,
  • Zbigniew Szymański MSc Eng., , phone number: +48 42 652 37 91.