For power transformer applications, this study explores an alternative insulating liquid. With this aim, edible natural esters such as refined Olea europaea (olive oil), rice bran oil, soya bean oil, sunflower oil, and corn oil are investigated as suitable replacements for the mineral oil (MO) used in the transformer. In addition, olive oil and other natural esters are incorporated into the blend for further analysis to obtain a better insulating medium. Blended natural esters were also tested for performance enrichment by antioxidant inclusion. Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were chosen as antioxidants for this study. In this study, we aimed to investigate the role of key input factors [A-speed, B-time, and C-temperature] on the output response [Y-breakdown voltage]. It was determined that the optimal conditions for [Y] are [A-699.91 rpm, B-49.95 min, and C-88.75 °C]. In order to ensure the desirable properties, the natural esters were subjected to certain experimentations such as breakdown voltage (BDV), viscosity, fire point (FeP), and flash point (FhP). From the results, it is observed that the natural esters and blended natural esters can be used in the transformer as an alternate insulating medium and that the antioxidants have a significant effect on the properties of natural ester combinations.
Keywords: Breakdown voltage; Central composite design; Fire point; Flash point; Natural ester oil; Viscosity.
© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.