220kV电力变压器抗短路能力的结构研究

发布时间：2018-02-01 01:20

本文关键词： 电力变压器短路失稳结构优化设计　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国坚强智能电网不断发展壮大,220kV电力变压器不断增强的抗短路能力,是保证电网安全稳定运行的重要基础。随着技术进步,电网发展,也不断扩大了电网的容量和范围,也大大增长了短路几率和短路电流,这就要求220kV电力变压器的抗短路能力更高。尤其大容量变压器,出现短路事故后,短路电流非常大,如果无法满足抗短路要求,大范围停电将会出现,糟糕后果将会产生,群众生活和社会生产将受损严重,影响巨大。220kV变压器作为输电线网中的非常重要的部分,电网如若不能稳定运行,很大一部分原因是其运行质量不好。工业用户用电量不断提高,电力缺口也显著增长,高压、大容量作为发展方向趋势日趋明显。电磁负荷对220kV电力变压器运行而言,所承受数值量很高,漏磁场被相应放大,但是电网的等效阻抗在变小,当系统短路时,电网中产生的短路电流数值的增加是成倍的,此时变压器被附加一系列严峻的问题,实际情况也是220kV电力变压器经常遭受短路冲击。近期很多220kV电力变压器发生事故。返厂检修发现,自身抗短路能力不强是造成短路损坏的一个很重要原因。这种故障的危害性显而易见,电网安全运行得不到保证。因此,抗短路能力作为一个出厂验收重要指标,是保证变压器长期安全运行的可靠手段。本课题通过研究电力变压器遭遇突发短路后发生绕组失稳以及结构件损坏的现象,探索优化措施,包括电磁计算、结构设计、工艺流程。并在实现抗短路能力的情况下,兼顾产品结构优化及效益。基于典型物理公式算法及有限元法,利用REST、Ansys等仿真分析软件,对220kV变压器进行进行抗短路能力、结构件强度仿真分析,各项措施能否达到相关要求得到了验证。通过以上研究,掌握了 220kV变压器与抗短路能力相关的内部结构特点。
[Abstract]:The strong smart grid in China is developing and strengthening the anti-short-circuit ability of 220kV power transformers, which is the important foundation to ensure the safe and stable operation of the power grid. With the development of technology, the power grid is developing. It also expands the capacity and range of power network and greatly increases short-circuit probability and short-circuit current, which requires 220kV power transformer to have higher anti-short-circuit capability, especially high-capacity transformer. After the short circuit accident, the short circuit current is very large, if can not meet the anti-short-circuit requirements, large-scale power outages will occur, bad consequences will occur, people's lives and social production will be seriously damaged. As a very important part of the transmission line network, if the power grid can not operate stably, a large part of the reason is that the operation quality is not good, and the power consumption of industrial users is increasing continuously. The power gap also increased significantly, high voltage, large capacity as the trend of development is becoming more and more obvious. Electromagnetic load on 220 kV power transformer operation, the numerical value is very high, leakage magnetic field is amplified accordingly. However, the equivalent impedance of the power network is becoming smaller. When the system is short-circuit, the value of the short-circuit current generated in the power network is multiplied, and a series of severe problems are attached to the transformer. The actual situation is that 220kV power transformers often suffer from short-circuit impact. Recently, many 220kV power transformers have accidents. The weak ability of resisting short circuit is a very important cause of short circuit damage. The harm of this kind of fault is obvious and the safe operation of power network can not be guaranteed. Short circuit resistance is an important indicator of factory acceptance. It is a reliable means to ensure the long-term safe operation of transformers. By studying the phenomenon of winding instability and structural damage after power transformers encounter sudden short circuit, the paper explores the optimization measures, including electromagnetic calculation. Structure design, process flow, and under the condition of anti-short-circuit ability, product structure optimization and benefit are given consideration. Based on typical physical formula algorithm and finite element method, REST is used. Ansys and other simulation analysis software, 220 kV transformer for short-circuit resistance, structural strength simulation analysis, the measures to meet the relevant requirements have been verified. Through the above research. The internal structure characteristics of 220 kV transformer related to short circuit resistance are grasped.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM41

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