The art of predicting the fate of a power transformer by into a cut of oil

This article presents the transformer oil features by which one must abide. These features are examined according to standards to ensure the oil’s integrity. Transformer-impregnated paper is the determining factor in transformer age, so it is discussed extensively.

The importance of insulation was increased over the years due to the increase in the voltage rating of transformers. Within the last decades, although research on transformer insulation and diagnosis methods have been improved so much, the insulation of HV transformers remained more or less unchanged, and for EHV and UHV transformers, the oil–paper insulation is dominant.

Transformer oil has elements indicative of the transformer’s overall health. For example, a DGA transformer oil test shows levels of gases like acetylene and ethylene rising above a safe limit. This indicates the aging of the transformer.