• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Study of electric discharge and space charge formation phenomena in the air gaps of an ice-covered insulator using an icicle/ice-covered plate electrode system.
【24h】

Study of electric discharge and space charge formation phenomena in the air gaps of an ice-covered insulator using an icicle/ice-covered plate electrode system.

机译：使用冰柱/覆冰板电极系统研究覆冰绝缘子气隙中的放电和空间电荷形成现象。

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 cold climate regions, ice accumulation on insulators decreases their insulating strength, sometimes resulting in flashover faults and the consequent power outages. This problem has been paid great attention by many researchers and a large number of publications and reports have been available. It was found that one of the most common evidence on ice-covered energized insulators is the presence of air gaps along the ice surface due to corona discharge activities.;This present thesis aims to study the fundamental and initial processes of electric discharge in the air gap on the ice-covered insulators, within the framework of the NSERC/Hydro-Quebec Industrial Chair on Atmospheric Icing of Power Network Equipment (CIGELE) and the Canada Research Chair on Atmospheric Icing Engineering of Power Network (INGIVRE), at the Universite du Quebec a Chicoutimi in collaboration with The Key Laboratory of High Voltage Engineering and Electrical New Technology of the Ministry of Education at Chongqing University (CQU). In order to simplify the study, a physical model, an icicle/iced-plate electrode system, is introduced based on numerous previous investigations to simulate the icicle tip and ice-covered insulator surface on real ice-covered insulators. Experimental investigations are systematically carried out in an artificial climate chamber in the High-Voltage Lab of CQU. Using a measurement system consisting of a ultra-violet camera, CoroCAM IV+, and a special-designed pulse current sensor, the corona discharge characteristics such as the corona inception voltage (Vinc), the discharge volume at Vinc, the repetition rate of discharge pulses, and the current pulse waveform are investigated in detail under different parameters. These parameters include the gap distance, the environmental temperature, the freezing water conductivity, the atmospheric pressure and the voltage polarities as well as the voltage types. Subsequently, the statistic analysis is applied to the experimental results and the influence of these parameters on the discharge current pulse characteristics is determined.;In order to reveal the physical mechanism underlying the corona discharge and determine the influence of space charge on the consequent discharge processes, a dynamic physics process of space charge is proposed to analyze this discharge phenomenon. A mathematical model is established to simulate the drift and diffusion process of the space charge clouds. From this model, the critical time of space charge clouds are calculated and are validated with the experimental results. Finally, the possible influences of space charge on the flashover of iced-covered insulators are analyzed and discussed.;The study results give a better understanding of the corona discharge at the tip of icicles on the ice-covered insulators. However, due to the time limitation and the complexity of this phenomenon, further studies are necessary to complete the model and theory. Several recommendations are proposed for future studies.;The corona discharge at the icicle tips in the air gap is the first stage of the flashover process. During these corona discharge activities, a large number of space charges, including the positive and negative ions, are generated and, in turn, they influence the electric field distribution in the air gap and the consequent sequential discharge activities. However, due to its invisible properties and its complexity, the influence of the space discharge on the electric field distribution and on the flashover process is generally ignored in previous studies.
机译：在寒冷的气候区域，绝缘子上的冰积聚会降低绝缘强度，有时会导致闪络故障和随之而来的停电。许多研究者已经高度关注这个问题，并且已经有大量的出版物和报告。已经发现，在冰覆盖的带电绝缘子上，最常见的证据之一是由于电晕放电活动而在冰表面上存在气隙。;本论文旨在研究空气中放电的基本和初始过程在NSERC /水魁北克电力网络设备大气覆冰工业主席（CIGELE）和加拿大大气网络结冰工程研究主席（INGIVRE）的框架内，冰覆绝缘子上的空隙与重庆大学高压工程与电气新技术教育部重点实验室合作的魁北克奇科蒂米。为了简化研究，在先前的大量研究基础上，引入了一个物理模型，即冰柱/覆冰板电极系统，以模拟真实冰覆绝缘子上的冰柱尖端和冰覆绝缘子表面。在CQU高压实验室的人工气候室中系统地进行了实验研究。使用由紫外线照相机，CoroCAM IV +和特殊设计的脉冲电流传感器组成的测量系统，可测量电晕放电特性，例如电晕起始电压（Vinc），Vinc处的放电量，放电脉冲的重复率，并详细研究了在不同参数下的电流脉冲波形。这些参数包括间隙距离，环境温度，冷冻水电导率，大气压和电压极性以及电压类型。随后，对实验结果进行统计分析，确定这些参数对放电电流脉冲特性的影响。；为了揭示电晕放电的物理机制，并确定空间电荷对随后放电过程的影响。提出了空间电荷的动态物理过程来分析这种放电现象。建立了数学模型来模拟空间电荷云的漂移和扩散过程。根据该模型，计算了空间电荷云的临界时间，并通过实验结果对其进行了验证。最后，分析和讨论了空间电荷对覆冰绝缘子闪络的可能影响。研究结果使人们更好地了解了覆冰绝缘子冰柱尖端的电晕放电。但是，由于时间限制和这种现象的复杂性，需要进一步研究以完善模型和理论。提出了一些建议，以供将来研究。气隙中冰柱尖端的电晕放电是闪络过程的第一阶段。在这些电晕放电过程中，会产生大量的空间电荷，包括正离子和负离子，它们依次影响气隙中的电场分布和随之而来的顺序放电活动。但是，由于其不可见的特性和复杂性，在以前的研究中通常忽略了空间放电对电场分布和闪络过程的影响。

著录项

  • 作者

    Yu, Defen.;

  • 作者单位

    Universite du Quebec a Chicoutimi (Canada).;

  • 授予单位 Universite du Quebec a Chicoutimi (Canada).;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 239 p.
  • 总页数 239
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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