• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Evaluation and protection of high voltage electrical equipment against severe shock and vibrations.
【24h】

Evaluation and protection of high voltage electrical equipment against severe shock and vibrations.

机译：评估和保护高压电气设备免受严重冲击和振动。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In recent moderate and strong seismic events, it was demonstrated that parts of the electrical power system are vulnerable to damage and their performance is strongly influenced by specific equipment design and installation practice. Some of the most complex and vulnerable components are: (i) disconnect switches and (ii) high power transformers. Each of these components has vulnerable parts which should be studied, evaluated and possibly protected in order to ensure continuous operation after earthquakes. This dissertation focuses on the two systems indicated above.;A disconnect switch used in substations of large electrical grids is an important component that supports the functionality of the electrical network. Such a switch is a combination of a support structure and the switching mechanism, which in turn is made of fixed and moving metal parts and of ceramic, or composite, electrical insulators. In order to determine if this equipment is acceptable in seismic areas, the static and dynamic characteristics of these high voltage three-phases disconnect switches and their capacity to withstand severe vibrations testing has to be performed. Due to the complexity of such systems and uncertainties in the construction and behavior of components, such determination cannot be done computationally.;In an attempt to determine contributions of components to the global response of the disconnect switch (DS) systems, this work proceeds with a methodical experimental and computational study. Tests to find the characteristics of each component were performed first, followed by tests of various subassemblies. Moreover, the entire assembly was also tested while observing the contributions of the individual components and sub-assemblies. When weak components were identified, a solution for protecting the components through modification of the response of the global system was attempted. The test results and the numerical evaluations showed several important characteristics in the behavior of the disconnect switches and issues in their acceptance testing (qualifications): The adequacy and acceptance of transformers and transformer bushings, is of great concern in the electrical industry. The current practice such as the IEEE 693-2005 recommends the following about the qualification tests of a transformer bushing: (i) using a rigid frame to hold the bushing on a shake table instead of using a real transformer tank and (ii) doubling input ground motions to consider the amplification of the ground motion caused by the flexibility of the transformer tank. The rigid frame lacks the capability to simulate the dominant effects of the local connectivity of the bushing to the transformer's cover, while the base motion recommended by the current code underestimates the effects of the influence of the tank walls and cover plate on the motion transmitted to the bushing at its connection to the tank. While a bushing is mounted on the roof (cover) of a transformer tank, the excitation transmitted to the bushing is not identical to the ground motion below the transformer tank. The roof motion is amplified (or attenuated) differently in the horizontal and vertical directions due to the dynamics of the tank. This study identifies the issues related to the acceptance testing and proposes, designs, develops, and evaluates experimentally and numerically a support frame simulating transformer behavior.;Due to limitations in reproducing simulated earthquake ground motions, seismic qualification testing is often limited to lower levels of shaking. In this study, the possibility of using a modulated sinesweep that can be implemented in smaller laboratories as an input base motion for qualification purposes is investigated. The sine-sweep proposed is modulated to match an arbitrary required response spectrum for electrical equipment (such as required by IEEE 693 RRS).;In addition to the existing methods to identify system frequencies and damping values specified in testing standards, an alternative method, i.e. a table impulse test, is developed and evaluated by analyzing testing results. A table impulse test can share most of advantages which can be found from the existing resonant frequency search test methods, while each existing method shares only one or some of those advantages. (Abstract shortened by UMI.)
机译：在最近的中等强度和强烈地震事件中，事实证明，电力系统的某些部分易受损坏，其性能受特定设备设计和安装实践的强烈影响。一些最复杂和易受攻击的组件是：（i）断开开关和（ii）大功率变压器。这些组件中的每一个都有易受攻击的部分，应对其进行研究，评估和可能的保护，以确保地震后能够连续运行。本文主要研究上述两个系统。大型电网变电站中使用的隔离开关是支持电网功能的重要组件。这种开关是支撑结构和开关机构的组合，该开关结构又由固定的和活动的金属部件以及陶瓷或复合材料的电绝缘体制成。为了确定该设备在地震地区是否可以接受，必须对这些高压三相断路开关的静态和动态特性及其承受剧烈振动的能力进行测试。由于此类系统的复杂性以及组件的构造和行为的不确定性，因此无法通过计算来进行这种确定。为了试图确定组件对隔离开关（DS）系统的整体响应的贡献，本工作将继续进行有条理的实验和计算研究。首先进行测试以找到每个组件的特性，然后进行各种子装配体的测试。此外，在观察单个组件和子组件的作用的同时，还对整个组件进行了测试。当确定了弱组件时，尝试了一种通过修改全局系统响应来保护组件的解决方案。测试结果和数值评估显示了隔离开关行为的几个重要特征以及其验收测试（合格）中的问题：变压器和变压器套管的充分性和验收是电气行业中非常关注的问题。当前的实践（例如IEEE 693-2005）建议对变压器套管的合格性测试进行以下建议：（i）使用刚性框架将套管固定在振动台上，而不是使用实际的变压器油箱；以及（ii）输入加倍地面运动时要考虑由变压器油箱的柔韧性引起的地面运动放大。刚性框架缺乏模拟套管与变压器盖的局部连通性的主要影响的能力，而当前法规建议的基本运动低估了罐壁和盖板对传递给发动机的运动的影响。衬套与水箱的连接处。当套管安装在变压器箱的顶部（盖）上时，传递到套管的激励与变压器箱下方的地面运动并不相同。由于水箱的动态性，车顶运动在水平和垂直方向上会有所不同地放大（或衰减）。这项研究确定了与验收测试有关的问题，并提出，设计，开发和评估了一种模拟变压器行为的支撑架。通过模拟再现地震地震动的局限性，地震鉴定测试通常仅限于较低级别的试验。颤抖。在这项研究中，研究了使用可在较小实验室中实现的调制正弦扫描作为输入基础运动以进行鉴定的可能性。提议的正弦扫描经过调制以匹配电气设备的任意所需响应频谱（例如IEEE 693 RRS所要求的）。除了用于识别测试标准中指定的系统频率和阻尼值的现有方法之外，还有一种替代方法，通过分析测试结果来开发和评估表脉冲测试。表格脉冲测试可以共享大多数优点，这些优点可以从现有的谐振频率搜索测试方法中找到，而每种现有方法仅共享这些优点中的一个或一些。 （摘要由UMI缩短。）

著录项

  • 作者

    Kong, Dohwan.;

  • 作者单位

    State University of New York at Buffalo.;

  • 授予单位 State University of New York at Buffalo.;
  • 学科 Engineering Civil.
  • 学位 Ph.D.
  • 年度 2010
  • 页码 476 p.
  • 总页数 476
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:37:09

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号