【作者】 吴延清；

【导师】 邹积岩；

【作者基本信息】 大连理工大学 ， 电机与电器， 2010， 博士

【摘要】 真空开关作为电力系统中控制和保护设备,具有熄弧能力强、体积小、重量轻、免维护、使用寿命长、无污染等优点,在电力系统中得到了迅速发展和广泛应用。真空开关电弧特性研究是当前开关电器领域的前沿课题之一,而短间隙真空电弧金属蒸气特性包括宏观电弧形态和微观金属蒸气等离子参数特性,是多断口高压真空开关和相控开关研发中的重要基础研究课题。本文首先简要回顾了国内外真空开关的发展历史与现状,综述了真空开关电弧的基本特性和前人的研究成果,引出短间隙真空电弧的研究在真空开关向高电压多断口和相控开关发展中的意义。本文以短间隙真空开关电弧为研究对象,主要研究内容和目标是通过实验诊断和计算机数值仿真来研究其形态特性和内部等离子体参数。为实验描述短间隙真空开关电弧,首先建立真空开关电弧的实验装置,构建包括可拆真空灭弧室的频率约为50Hz的电源回路和基于CMOS高速图像采集系统。通过该系统对真空电弧进行高分辨率的高速图像采集,实现对短间隙真空开关电弧形态特性的深入分析。为得到高质量的电弧图像,课题还建立了基于高精度CCD真空开关电弧图像采集系统,为电弧内部金属蒸气等离子体参数分析提供实验基础。为使触发电路和电弧图像采集系统能够同步工作,设计了同步控制电路。将光学技术和数字图像处理技术应用到真空开关电弧诊断之前,需要用数字图像处理技术对真空开关电弧图像进行预处理,提取真空开关电弧的几何特征。然后对电弧燃烧过程中的扩散运动特征进行分析,研究电弧图像的灰度分布特征及其等值线,最后结合图像粒子测速技术,利用Delphi对真空开关电弧的粒子相对位移和相关性进行诊断。为理论描述大电流短间隙真空电弧行为,本文以离子和电子的双流体模型及麦克斯韦方程为基础,建立短间隙真空电弧的二维稳态磁流体力学模型,并进行数值模拟,分析电弧扩散过程中的电磁现象和传热过程,研究过程参数和外部电参数对电弧特性的影响和外部端口特性的影响。同时通过仿真数值计算,得到真空电弧等离子体参数的分布。最后,本文利用短间隙真空开关电弧动态仿真实验,研究电弧电流过零后的电弧过程,对真空间隙中弧后剩余电弧等离子体的扩散过程进行分析,研究真空间隙中能量控制,并对灭弧室内局部电场进行优化。本文作为国家自然科学基金重点项目“金属蒸气电弧等离子体调控理论及在高压断路器领域中的应用”(E50537010)重要组成部分,运用现代先进光学技术、计算机图像处理技术和计算机仿真技术对短间隙真空开关电弧的宏观形态特性进行了研究,可支持新一代智能化高压真空开关的基础理论与开发。更多还原

【Abstract】 VCB(Vacuum circuit breakers) as controlling and protecting devices in power system,have many advantages,such as powerful extinction capability,small in size, light in weight, maintenance-free, long working-life, no pollution etc.,which have been widly applied in the power system. At present, researches on vacuum switches are important subjects of the advanced topics in the electrical switches filed. The features of vacuum arc in short gap including macro arc modes and micro characteristics of metal vapor, are very important and foundational research in the design of multi-breakers high voltage vacuum switches and intelligent phase-control switches.This paper briefly reviews the overseas and dometic developing history and the status of VCB, which summarizes the basic characteristics and former achievements of VCB. And then educe the developing significance of multi-breakers switches’s application in high-voltage velel and intelligent phase-control switches is put forward. In this paper, vacuum switching arc in short gap is researched using experiments and computer simulation, the forms and inner plasma parameters are the proposed content and objectives of this studyTo describe vacuum switching arc in short-gap by experiments, vacuum arc experimental device is established, which includes a power supply circuit whose frequency of removable vacuum room used to extinguish arc are about 50Hz, and a high-speed image acquisition system based on CMOS.Using the high-speed image acquisition of the vacuum arc, we can analy morphological characteristics of vacuum switching arc in short gap. Besides, a set of high precision and high-resolution image acquisition system based on CCD is established, through which the arc of high-quality images can be obtained so that we can get experimental basis for plasma parameters within the metal vapor arc. We design a synchronous control circuit of vacuum switch arc to make the trigger circuit and arc synchronization of image acquisition work at the same time.To use optical and digital image processing technology in the diagnosis of vacuum arc.Firstly vacuum switching arc image is preprocessed by digital image processing, then the vacuum switch arc geometry is extracted and the burning process of diffusion combustion characteristics are analyzed, while the gray image distribution and its contour lines were drawn. Lastly, relative displacement and correlation of arc vacuum switch particles are diagnosed by image particle velocimetry technology and Delphi. In the paper, to describe the high-current short gap vacuum arc behavior in interrupters, a model of two-dimensional steady-state short gap vacuum arc is established based on the two-fluid model of ions and electrons and Maxwell’s equations. Electromagnetic phenomena and heat transfer process are studied in the diffusion process of the arc. The influence of external electrical parameters on the arc characteristics and the characteristics of the external ports are reseached.By calculating and simulating, it also obtain the distribution of vacuum arc plasma parameters.At last, we use short gap vacuum switch arc dynamic energy analysis to study the arc phenomena after zero, and analyze the diffusion process of remained arc plasma in vacuum arc gap and control the vacuum gap of energy, optimize the local electric field distributions inside the chanmeber,to guide the design of vacuum chamber in short-gap.In this paper, vacuum switching arc macro-morphological characteristics are studied by using modern advanced optical technology, Digital image processing technology and computer simulation, which is an important part as a key project of National Natural Science Foundation of China. It can support the theoretics research and development of new generation of intelligent VCB.更多还原