Study of Aging and Determination of Optimum Hydrocarbon Composition of Transformer Oil

Optimizing the composition of the transformer liquid insulation to increase its service life was the main objective of this study. The development of the power industry without introduction of additional power-generating equipment, including oil-filled transformers. Used as a liquid insulation and heat dissipating medium, transformer oil has a significant impact on the smooth, durable operation of the transformer. Transformer oil is operated in power facilities of industry under the action of an electric field at high temperatures, which accelerates the aging process of liquid insulation. The thermal stability and oxidation resistance of the transformer oil electric field largely depends on its hydrocarbon composition. To determine the influence of the hydrocarbon composition on the aging rate of the oil, model mixtures with different hydrocarbon composition and with the addition of different concentrations of aromatic hydrocarbons were used. The model mixtures contained paraffin-naphthene hydrocarbons with the addition of various mono-and bicyclic hydrocarbons. The destruction of the transformer oil was experimentally evaluated based on the amount of precipitation formed, the concentration of water, the tangent of the dielectric loss angle. During the study the influence of the aromatic hydrocarbon concentration on the operational properties of model mixtures has been determined. Model mixtures consist of aromatic hydrocarbons (concentration close to 8.6%); a change in the indicated concentration can lead to a negative increase in the characteristics of the transformer oil. Based on mathematical studies, the functional dependences describing the impact of aromatic hydrocarbons concentration on the operational characteristics of the oil were obtained. As a result of optimization of the obtained dependencies, the optimum concentration of aromatic hydrocarbons has been found, which provides high operational performance.