大型电力变压器附加损耗与温度场分析

发布时间：2018-11-05 19:50

【摘要】：随着我国经济的迅速发展,人们对电能的需求与日俱增,电网规模和发电机的单机容量随之不断增加,而电力变压器作为发电厂和变电所的主要设备,随着变压器容量的增加,变压器漏磁场随之增大,由此产生的各种附加损耗增多,并带来可能出现局部过热等问题,降低变压器的绝缘性能,最终影响变压器的安全稳定运行以及使用寿命。所以,对变压器的损耗分布以及温度场的深入研究是十分重要的。本文首先对电磁场和变压器漏磁场的相关理论进行了简单的介绍,以一台SZ10-120000/220三相五柱式电力变压器为例,建立了求解变压器漏磁场的三维模型,利用有限元软件仿真求出变压器漏磁场的分布,并在此基础上,通过计算每根导线的涡流损耗以及各金属结构件的涡流损耗,进而得到绕组和各结构件的涡流损耗分布情况和总的损耗值,并计算分析了油箱和夹件在加设磁屏蔽情况下的涡流损耗分布,为改善金属结构件涡流损耗的措施指明了方向;最后利用FLUENT软件建立了求解电力变压器温度场和油流场的二维模型,得到了变压器的温度场和流体场的分布,并仿真对比了加设与不加挡油板情况下的温度场和油流场分布,结果表明增设挡油板为改善变压器的流场及温度场分布有一定作用。通过对电力变压器漏磁场、绕组以及金属结构件的涡流损耗的计算和分析,得到了绕组和金属结构件的涡流损耗分布情况以及变压器温度场分布,能为工程上更合理的设计以及结构的优化提供一定指导意义。
[Abstract]:With the rapid development of economy in our country, the demand for electric energy is increasing day by day, the scale of power grid and the single machine capacity of generator are increasing. As the main equipment of power plant and substation, power transformer is increasing with the increase of transformer capacity. With the increase of leakage magnetic field of transformers, various additional losses are increased, and some problems such as local overheating may occur, which will reduce the insulation performance of transformers and ultimately affect the safe and stable operation and service life of transformers. Therefore, it is very important to study the loss distribution and temperature field of transformer. In this paper, the theory of electromagnetic field and leakage magnetic field of transformer is introduced briefly. Taking a SZ10-120000/220 three-phase five-column power transformer as an example, a three-dimensional model for solving leakage magnetic field of transformer is established. The distribution of leakage magnetic field of transformer is simulated by finite element software. On the basis of this, the eddy current loss of each wire and the eddy current loss of each metal structure are calculated. The eddy current loss distribution and the total loss value of the windings and structural parts are obtained, and the eddy current loss distribution of the oil tank and the clamping parts under the condition of magnetic shielding is calculated and analyzed, which points out the direction for improving the eddy current loss of the metal structure parts. Finally, a two-dimensional model for solving the temperature field and oil flow field of power transformer is established by using FLUENT software, and the distribution of temperature field and fluid field of transformer is obtained, and the distribution of temperature field and oil flow field under the condition of adding and without oil retaining plate is simulated and compared. The results show that the addition of oil retaining plate can improve the distribution of flow field and temperature field of transformer. Through the calculation and analysis of the leakage magnetic field of power transformer, the eddy current loss of winding and metal structure, the distribution of eddy current loss of winding and metal structure and the distribution of transformer temperature field are obtained. It can provide some guidance for more reasonable design and optimization of structure in engineering.
【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】：TM41

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