As the polarity of natural ester fluids is higher than that of mineral oils, these fluids will admit higher amounts of water in solution before reaching saturation level. Most of the available literatures are also based on these issues only.. transformer oil is an oil in which the transformer is submersed to electrically insulate the transformer windings, and also to cool the machine this makes sure, that there are no corona discharges or sparkings and electrically the machine remains safe! Figure 5 (left) clearly indicates that the reduction in DP of pressboard insulation in the presence of natural esters is substantially lower than in those transformers filled with mineral oils. Effects of dissolved gases are partial discharge, low energy discharge, arching, and high temperature. Its functions are to insulate, suppress corona and arcing, and to serve as a coolant. Paraffin is less soluble than Naphtha oil. Most of the data available is experimental. Change of moisture in PB over aging. trailer 7 (1961). Solubility/partition coefficients k of gases in mineral and non-mineral fluids at 20°C, Table 3. Transformer oils are mineral oils, dissolved gases, Paraffin, Naphtha, and hydrocarbon. This is a preview of subscription content, log in to check access. The cause of neutralization in transformer oil is due to the aging of oxidation. Transformer oil or insulating oil is usually a highly-refined MINERAL OIL that is stable at high temperatures and has excellent electrical insulating properties. Synthetic esters mainly produce short chain acids and these acids accelerate the ageing process of paper insulation creating corrosion on copper conductors. 0000004873 00000 n 2. 0000005601 00000 n Lubricating oil is generally composed of two parts, a base oil and an additive, which can lubricate, clean, cool, seal, reduce, rust and prevent the engine. Cheim at al [5] have reported the existence of a linear relationship between DP value of cellulose paper insulation and 2-FAL concentration dissolved in mineral oil in logarithm scale. What is the chemical composition of the Transformer oil or insulating oil? That is why this oil is also known as Mineral Insulating Oil. Degradation of cellulose insulation releases water, and hydrolysis reactions in ester fluids in a transformer could become extensive with time. L. Cheim, D. Platts, T. Prevost, S. Xu, “Furan Analysis for Liquid Power Transformers”, By entering your data in the form provided herein and becoming Consultants Corner Member, you are accepting our Privacy Policy available. 51–53, May, 1967. Moisture content of the two insulating fluids at RH 50% and variable temperature, Figure 2. This is most likely due to the amount of unsaturated, non-aromatic molecules as compared to mineral oils [2]. Paraffin: Paraffin is a colorless, odorless solid substance which can’t soluble in water and does not easily react with any reagent. Typical specifications are: flash point 140 °C or greater, pour point −40 °C or lower, dielectric breakdown voltage 28 kV (RMS) or greater. The DP value decrease in natural ester filled units was negligibly small during the experimental period, and the DP was 100 to 150 higher than the DP of pressboard aged in mineral oil. In this article, we will focus on the chemical-based techniques for condition monitoring available in the industry. silicone fluid, natural ester, and synthetic ester. Learn more about Institutional subscriptions. 87 0 obj<>stream A GUIDE TO TRANSFORMER OIL ANALYSIS BY I.A.R. With higher polarity than that of mineral oils, natural ester fluids will admit higher amounts of water in solution before reaching saturation level. When the additive 2, 6-di-tert-butyl-4-methylphenol (ionol) is used in a fraction of monocyclic aromatic hydrocarbons isolated from a transformer oil distillate, it retards the processes of resin formation and the increase in tan δ.