Ageing analysis of insulating oil under various atmospheric conditions

Basically transformer oil is a petroleum by-product. At the time of petroleum refining process, we get pure transformer oil without any water content. Due to the atmospheric conditions and working conditions humidity is added with transformer oil there by water content in transformer oil increases during the transformer filling up process which leads to increase in water content in the oil. This accelerates ageing of oils. In this work, water content in insulating oil is increased artificially by varying the humidity level´s using humidity chamber. After that, humidified insulating oil is constantly heated up to 100 hours at 95°C. Breakdown voltage (BDV), Acidity, Tan delta, water content and Inter facial tension (IFT) of transformer oil are analyzed. Finally results were compared for transformer oil with and without humidity to find out ageing rate of insulating oil.