Physical And Chemical Properties Simulation Of Natural Ester Oil Paper Insulation System

The power transformer is the core equipment of energy conversion in the power system.It undertakes a very important task of transmission and distribution in the modern power grid.The failure of the power transformer will cause a serious threat to the safe and stable operation of the power grid and bring huge economic losses.Therefore,the accurate diagnosis and analysis of the operation status of the active power transformer equipment,and then the prediction of its remaining life,can provide an important reference for the maintenance and repair of the power transformer,and has important theoretical and practical significance for improving the reliability and economy of the safe operation of the power transformer.As the most important insulation method of modern transformer,oil paper insulation of power transformer is widely used in oil immersed transformer.With the development and progress of modern power grid technology,people's awareness of safety and environmental protection is gradually enhanced,and the requirements for various indicators of transformer oil paper insulation are becoming more and more stringent.Although traditional mineral insulating oil has good electrical and cooling performance,its disadvantages of low ignition point and poor natural degradation performance are increasingly inconsistent with the development concept of modern safety and green production.In many cases,it has The applicability under special conditions has become controversial.Therefore,the natural ester vegetable insulating oil with high ignition point and easy natural degradation has been widely used as a good substitute for mineral insulating oil.In this paper,using molecular dynamics simulation technology,considering the actual operating conditions of oil paper insulation system of power transformer at 70? and 101 KPa,the molecular dynamics model of natural ester transgenic vegetable oil and cellulose insulation board is constructed,and the actual operating environment of power transformer is set in the simulation,so as to achieve more close to the actual purpose.In order to study the physical and chemical properties of plant oil,such as the movement behavior of furfural under different moisture content and the micro water diffusion in oil paper composite insulation system,the results of experiment and simulation are introduced for comparative analysis.The main research results are as follows:(1)The water content in vegetable oil has a great influence on the diffusion of furfural.The increase of water content will reduce the viscosity of the vegetable oil molecules,which is the decrease of the movement obstacles between the molecules and the increase of the free volume of the whole system,thus providing a space basis for the diffusion of furfural molecules in the vegetable oil.(2)With the increase of water content,the interaction energy between furfural and the whole plant oil system will increase as a whole.The analysis of the increased energy shows that the increase of the overall energy is mainly due to the hydrogen bond between water molecules and plant oil molecules.With the increase of water content,the water particles are concentrated on triglyceride carbonyl to form hydrogen bond,and the plant oil will gradually become saturated,and the furfural molecules will gradually become saturated the binding effect will be reduced and the diffusion behavior will be strengthened.(3)The micro water diffusion behavior in the oil paper insulation system composed of vegetable oil and cellulose paperboard is studied by simulation.It is found that the diffusion of water molecules in the composite model has certain directionality.The pure vegetable oil model is compared with the model of initial water distribution in the vegetable oil,in which the mean square displacement of water molecules diffusion shows a high correlation,indicating that the vegetable oil molecules have more influence on the water molecules Strong adsorption.(4)Water molecules with initial water distribution in cellulose tend to diffuse into vegetable oil and form stable hydrogen bond structure in the simulation.The results of molecular dynamics simulation and energy analysis explain the diffusion process and reason of water molecules in the model.