Performance evaluation of natural Olea europaea (olive oil)-based blended esters with butylated hydroxyanisole and butylated hydroxytoluene: optimization using response surface methodology

Abstract

In this paper, an effort is made to develop the alternate insulating liquid for the power transformer applications. With that aim, the edible natural esters such as refined Olea europaea (olive oil), rice bran oil, soya bean oil, sunflower oil and corn oil are investigated as the suitable replacement for the mineral oil (MO) used in the transformer. Also, the blended natural esters are made with olive oil and other natural esters for further analysis with the above aspiration for better insulating medium. The effect of antioxidants inclusion is also studied for analyzing the performance enrichment of blended natural esters. Butylated hydroxyanisole (BHA) and Butylated hydroxytoluene (BHT) were chosen as antioxidants for this work. In this study, we aim 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 condition for the [Y] is at [A] of 699.91 rpm, [B] of 49.95 min, and [C] of 88.75 ℃.In order to ensure natural esters are desirable, some critical properties are measured, such as Breakdown Voltage (BDV), viscosity, fire point (FeP), and flash point (FhP). In accordance with international standards such as American Society for Testing and Materials (ASTM) and International Electrotechnical Commission (IEC), measurements are conducted. From the results, it is observed that the natural esters and blended natural esters have the ability to use in the transformer as alternate insulating medium and also the antioxidants have the significant effect on the properties of natural ester combinations.