超高压电力变压器绕组短路电磁力的计算与分析

发布时间：2018-03-03 01:16

本文选题：变压器　切入点：绕组　出处：《华北电力大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文以一台型号为SFPZ10-240000/330的三相双绕组有载电力变压器为例，计算了该变压器在发生单相对地短路时的瞬态电磁场、瞬时短路电流、短路电磁力，并根据国家标准规定的方法对绕组的短路强度进行了验证，取得了具有理论意义和工程实用价值的成果。为大型、超高压电力变压器绕组短路电磁力的计算和验证供了参考依据。本文主要由三部分内容组成。第一部分概述了我国电力变压器的发展现状、近年来变压器短路的事故情况，并对超高压电力变压器绕组短路电磁力计算的目的和意义进行了论述；介绍了国内外对短路试验、电磁仿真软件和漏磁场、短路电磁力以及绕组强度等问题的研究概况；在对电磁场理论、有限元分析和MagNet软件进行介绍的同时叙述本文所要进行的主要工作。第二部分提出瞬态电磁场、瞬态短路电流以及短路力的计算方法，，利用MagNet软件建立了变压器单相短路的有限元计算模型，模拟变压器突发短路的试验状态，分别对变压器低压绕组突发短路时的二维瞬态电磁场、瞬时短路电流、短路电磁力进行了计算和分析；得到了在0.25s的短路时间内绕组的轴向和幅向漏磁场的空间分布、短路电流波形、绕组各线饼单元的辐向和轴向短路电磁力的分布，并对短路时绕组线饼导线的应力进行了计算。第三部分选取一台通过短路试验的型号为SFZ11-120000/220的电力变压器,采用GB1094.5-2008中规定的方法对本算例产品的抗短路能力进行了验证；验证结果表明，本算例产品具有足够的抗短路能力。
[Abstract]:Taking a three-phase double-winding loaded power transformer as an example, the transient electromagnetic field, instantaneous short-circuit current and short-circuit electromagnetic force of a three-phase double-winding power transformer with single relative ground short circuit are calculated in this paper. The short-circuit strength of the winding is verified according to the method stipulated by the national standard, and the results with theoretical significance and practical engineering value are obtained. The calculation and verification of short-circuit electromagnetic force in UHV power transformer windings are provided for reference. This paper is mainly composed of three parts. The first part summarizes the development status of power transformers in China, the short circuit accidents of transformers in recent years. The purpose and significance of calculation of short-circuit electromagnetic force in winding of UHV power transformer are discussed, and the research situation of short-circuit test, electromagnetic simulation software and magnetic field leakage, short-circuit electromagnetic force and winding strength are introduced. In this paper, the theory of electromagnetic field, finite element analysis and MagNet software are introduced, and the main work of this paper is described. In the second part, the calculation method of transient electromagnetic field, transient short-circuit current and short-circuit force is presented. The finite element calculation model of transformer single-phase short-circuit is established by using MagNet software to simulate the test state of transformer sudden short-circuit. The 2-D transient electromagnetic field, instantaneous short-circuit current and short-circuit electromagnetic force of transformer low-voltage winding with sudden short-circuit are calculated and analyzed respectively, and the spatial distribution of axial and amplitude-leakage magnetic field of the winding is obtained in 0.25 s short circuit time. The waveform of short circuit current, the distribution of radial and axial short circuit electromagnetic force of each wire unit of winding, and the stress of winding wire during short circuit are calculated. In the third part, we select a power transformer which passes short-circuit test as SFZ11-120000/220, and verify the anti-short-circuit ability of this example by the method specified in GB1094.5-2008, and the result shows that this example has enough anti-short-circuit capability.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM41

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