Rapid determination of oxidation stability for transformer oils with antioxidant

The service life of transformer oil is directly influenced by oxidation stability of the oil. However, the standard method of ASTM or IEC to assess oxidation stability of transformer oil is very time-consuming. After 2 h of accelerated aging of transformer oil at specified conditions of temperature, oxygen flow rate and catalyst, the consumption rate of antioxidant was measured by high performance liquid chromatography. By researching the relation between the consumption rate of antioxidant and acid value after 164 h oxidation, the quick assessment method for oxidation stability of transformer oil with antioxidant was established, and the assessment criterion for this method was proposed. The feasibility of the method, with its advantages of rapidness and easiness, has been proved through experiments using samples of in-operation transformer oil.