基于磁场和温度场分析的自耦变压器容量优化研究

发布时间：2018-07-16 14:32

【摘要】：随着我国高速铁路的快速发展,AT供电方式已成为我国电气化铁路供电的首选。AT供电专用自耦变压器(以下简称"自耦变压器")作为AT供电系统中的关键设备之一,其容量的选择不仅关系到电气化铁路的供电安全性还影响着运营成本。根据铁路部门统计,牵引变压器普遍存在着容量浪费的问题,由于自耦变压器负荷特性相似,因此也存在同样问题。为了提高自耦变压器的容量利用率,降低铁路部门的运营成本,有必要在保证牵引供电安全、可靠的前提下,对容量进行优化。本文首先利用Ansoft Maxwell电磁仿真软件建立了 OD-25000/55型自耦变压器三维模型,运用电磁场理论和有限元法,对其进行了系统的研究。通过变压器安匝平衡原理验证模型的正确性,模拟了自耦变压器在空载时的铁心损耗分布情况,据此对变压器铁心进行了分块划分;计算并分析了变压器绕组的漏磁场分布情况,提取了各个绕组中的横向和纵向漏磁密值及其对应的涡流损耗值。然后利用Ansys Fluent有限元软件建立了 OD-25000/55型自耦变压器的数值计算模型,仿真分析了额定状态下稳态时其内部温度场分布情况。探究了机车电流与绕组电流的关系,机车运行状态对绕组电流的影响,以及AT变电所供电距离和机车时速对自耦变压器负载时间的影响,并研究了不同负荷特性下自耦变压器的温升特性。最后计算了三种不同容量自耦变压器的结构,分析了外部环境对寿命损失的影响。基于计算负荷下不同容量自耦变压器的温升特性分析了相应的寿命损失情况,并根据此负荷特性选取合适的自耦变压器容量,分析不同容量自耦变压器在相同负载下的经济性。在满足温升限值要求以及绝缘寿命损失情况的前提下尽量减小变压器容量,从而减少电费支出,提高铁路的经济效益。
[Abstract]:With the rapid development of China's high speed railway, the AT power supply mode has become the first choice of the.AT power supply special autotransformer (hereinafter referred to as "autotransformer") as one of the key equipment in the AT power supply system. The selection of its capacity is not only related to the power supply safety of the electric gasification railway, but also the operation cost. According to the statistics of the railway department, there is a common problem of capacity waste in traction transformers. Because of the similar load characteristics of the autotransformer, there are the same problems. In order to improve the capacity utilization of the autotransformer and reduce the operation cost of the railway department, it is necessary to optimize the capacity under the premise of ensuring the safety and reliability of the traction power supply. In this paper, the three-dimensional model of OD-25000/55 type autotransformer is established by using the Ansoft Maxwell electromagnetic simulation software. The theory of electromagnetic field and the finite element method are used to study the model. The correctness of the model is verified by the principle of the transformer ampere turn balance, and the distribution of the iron core loss when the autotransformer is no-load is simulated. The core of transformer is divided into blocks. The leakage magnetic field distribution of transformer winding is calculated and analyzed. The transverse and longitudinal magnetic flux leakage density in each winding and its corresponding eddy current loss value are extracted. Then the numerical calculation model of OD-25000/55 type autotransformer is established by using Ansys Fluent finite element software, and the simulation analysis is made. The distribution of internal temperature field in the steady state at the rated state, the relationship between the locomotive current and the winding current, the influence of the locomotive running state on the winding current, the influence of the power supply distance of the AT substation and the locomotive speed on the load time of the autotransformer, and the temperature rise characteristics of the autotransformer under different negative lotus characteristics are studied. Finally, the temperature rise characteristic of the autotransformer is studied. The structure of three different capacity autotransformer is calculated, and the influence of the external environment on the life loss is analyzed. Based on the temperature rise characteristic of the autotransformer with different capacity under the calculation load, the corresponding life loss is analyzed, and the appropriate capacity of the autotransformer is selected according to the load characteristic, and the autotransformer of different capacity is analyzed in phase. Under the same load, the capacity of the transformer is reduced as much as possible to meet the requirements of the temperature rise limit and the loss of insulation life, thus reducing the cost of electricity and improving the economic efficiency of the railway.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U223

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