油浸式电力变压器温度场及水分扩散分析

发布时间：2018-05-16 05:42

本文选题：变压器 + 加热　；参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：电网的运行离不开电力变压器的正常工作,变压器的正常工作对电能传输的稳定性、经济性有极大的意义。电力变压器受潮将会严重影响它的正常使用,变压器绝缘纸板中微水含量的增加会严重降低绝缘油纸的机械强度和电气强度,绝缘纸板中微水含量加倍,则其机械寿命减半,热老化速度也加倍。因此对受潮变压器的干燥除水至关重要。目前,传统变压器干燥方法存在多种缺陷,短路干燥法是未来干燥变压器的发展趋势,为了能更深入的探究短路干燥法的干燥效果,对变压器通入短路电流后温度场的分布及水分在不同温度下的迁移效果进行研究是十分有必要的。本文通过温度场及流场的相关理论,以一台SFSZ11-63000/220油浸式电力变压器为例,在不影响仿真结果的前提下,对变压器的结构进行合理的简化。将变压器模型图导入FLUENT软件,设置边界条件,通过改变电流密度的大小,得出不同负载下变压器的温度场分布情况,对变压器温度变化趋势、最热点位置、变压器油流速、负载变化对热点温度的影响进行分析,为变压器干燥选取合理的短路电流提供理论依据。结合油水平衡的相关理论知识,根据绝缘纸板中水分向绝缘油中扩散的边界条件,得出不同温度情况下,绝缘纸中水分随时间及厚度的变化及绝缘纸中平均水分含量变化趋势,为变压器干燥效果的研究提供理论参考。
[Abstract]:The operation of power grid is inseparable from the normal operation of power transformers, and the normal operation of transformers is of great significance to the stability and economy of power transmission. The moisture of power transformer will seriously affect its normal use. The increase of micro-water content in the insulation paper board of transformer will seriously reduce the mechanical and electrical strength of insulating oil paper. If the content of micro-water in the insulating paper board is doubled, the mechanical life of the insulation paper board will be halved. The rate of thermal aging also doubled. Therefore, it is very important to dry and dewater the damp transformer. At present, there are many defects in the traditional transformer drying method. Short-circuit drying method is the development trend of the future drying transformer. In order to explore the drying effect of short-circuit drying method more deeply, It is necessary to study the distribution of temperature field and the effect of moisture migration at different temperature after the transformer enters short-circuit current. Based on the theory of temperature field and flow field, this paper takes a SFSZ11-63000/220 oil-immersed power transformer as an example and simplifies the structure of the transformer without affecting the simulation results. The transformer model diagram is imported into FLUENT software, and the boundary condition is set. By changing the current density, the temperature field distribution of the transformer under different loads is obtained, and the transformer temperature change trend, the most hot spot, the flow rate of transformer oil are obtained. The influence of load change on hot spot temperature is analyzed, which provides theoretical basis for selecting reasonable short-circuit current for transformer drying. Based on the theoretical knowledge of oil-water balance, according to the boundary conditions of water diffusion from insulating paper to insulating oil, the variation of moisture content with time and thickness and the change trend of average moisture content in insulator paper at different temperatures are obtained. It provides a theoretical reference for the study of the drying effect of transformer.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM411

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