Degradation studies of electrical, physical and chemical properties of aged transformer oil

Abstract

Transformer is crucial equipment in the transmission of electric power. Various types of insulating materials used in the transformer among those mineral oil or transformer oil is used for the insulation. To reduce the failure percentage of transformer it is necessary to maintain the purity of oil. This paper investigates work on different properties of aged transformer oils and pure transformer oil. The aged oils are taken as filtered and unfiltered after using in the transformer. The electrical, physical and chemical properties are investigated for pure and aged transformer oils. UV-spectroscopy is used to test the quality of oil based on the absorbance value and FTIR analysis is performed to determine the functional groups existing in the pure and aged transformer oils. The results showed that breakdown strength is less for used transformer oil due to formation of acidic functional groups. The absorption peak is high for unfiltered oil followed by filtered oil and pure oil.