Comparative Study of Liquid Insulating Materials for High Voltage Transformer

In recent years, the latest technology, Gas-to-liquid (GTL) has been developed as an alternative to mineral oil. Natural ester oil is derived from vegetable oil. It is biodegradable, non-toxic, non-flammable, and has a higher breakdown voltage. Compared to conventional mineral oils and natural ester oils, GTL based oils are designed with a high level of composition and consistent performance, high purity, excellent resistance to degradation and are essentially sulfur free. In this study, GTL oil, mineral oil and natural ester oil will be compared in performance. Tests carried out for GTL oil, mineral oil and natural ester oil are tests of color scale and appearance, acid content, viscosity, moisture or water content, dielectric losses, breakdown voltage, and Dissolved Gas Analysis (DGA). Increased contaminants and free radicals cause an increase in dielectric losses and a decrease in oil resistivity. In addition, a strong correlation was found between the relative water content of oil and the breakdown voltage.