The influence of service aging on transformer insulating oil parameters

This paper investigates the influence of service aging on transformer insulating oil. Samples of 10 working power transformers of 16 to 20 MVA installed at different substations in Punjab, India have been taken. Various properties of transformer insulation oil such as breakdown voltage (BDV), moisture, resistivity, tan delta, interfacial tension and flash point have been measured using different national and international standards. In this paper, the various properties of insulating oil have been graphically presented with service aging.