【作者】 董华军；

【导师】 邹积岩；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2009， 博士

【摘要】 真空开关是电力系统中的控制和保护设备之一,相对其它介质开关,真空开关具有很多优点,目前在我国中压电力系统领域的应用已达到80%以上。多断口真空开关和相控开关是真空开关两个重要的发展方向,而制约两种开关发展的一个共同技术难题就是小开距真空电弧相关理论及其调控规律的研究,从而引出了本文的研究对象。电弧形态是真空电弧的外在重要特征,电弧等离子体是电弧的内在重要特征,将电弧的外在特征变化规律和其内在特征变化规律有效的结合一起并加以控制是真空开关电弧领域的重要研究课题。基于此,本文提出了基于高速摄像机CMOS(Complementary Metal OxideSemiconductor)电弧形态外在特性研究及基于数字图像处理技术CCD(Charge CoupledDevices)电弧等离子体参数诊断,为下一步电弧调控理论的研究奠定了实验基础。为了从电弧图像中提取真空电弧信息特征,对电弧图像实施数字图像处理技术是必不可少的环节。首先对图像数字处理识别中的图像格式和精度等相关技术进行了叙述,运用中值滤波方法对CCD图像进行噪声滤波;然后直方图均衡化对电弧图像进行增强处理,运用Canny算子对电弧的轮廓进行提取,对电弧的几何特征面积和周长进行分析;为了增加电弧图像的视觉效果,对电弧图像的灰度等值线进行了绘制;且对电弧图像进行了伪彩色显示,这些工作可为真空开关电弧图像的数据信息的挖掘提供有力的工具。为了实现对真空开关电弧形态的研究,本文根据真空开关灭弧室模型,建立真空开关电弧的实验装置,包括可拆真空灭弧室,频率约为50Hz的电源回路,电弧伏安特性的检测装置等;建立了一套基于CMOS高速图像采集系统,对真空电弧进行高分辨率的高速图像采集。结合采集的图像,对真空电弧燃烧过程进行研究,提出真空电弧图像轴向截面积扩散速度概念,分析电弧燃烧过程中电弧轴向截面积变化过程及影响其变化的三大因素:真空间隙、电压等级和磁场。为了从图像信息中得到电弧等离子体的参数,本研究选用了高精度的CCD相机,建立了基于数字图像处理技术CCD电弧等离子体参数的诊断系统。基于辐射理论建立了真空开关电弧等离子体参数诊断数学模型,结合Abel逆变换计算,通过该实验装置及诊断模型,对真空开关电弧等离子体参数——电子温度和电子密度进行诊断。最后本文为了验证光学方法诊断的实验结果,利用Langmuir探针诊断系统对真空开关电弧等离子体参数诊断,对两种方法得到的实验结果进行对比分析研究。本文探讨真空开关电弧外部形态特征和内部等离子体参数的诊断,旨在提出相应的调控理论以提高开关装置的工作性能和指标,完成电力系统的保护和控制任务。本课题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”(No.50537010)的一部分,开展了真空开关电弧形态特征和其等离子参数特征研究,完成了相应的实验理论计算,并为进一步的调控理论提出提供了实验基础。更多还原

【Abstract】 As one of the controlling and protecting devices in modern power system, VCBs have several advantages over other switches; nowadays they have been widely applied in industries and agricultures with the rapid development of power supply market, accounting for over 80 percent in China. VCB with multiple breaks and synchronous switching have become important developing of VCB, their common technical problem is researches on the related theory of vacuum arc in short-gap and its controlling regularity, which is the research object in this paper. Arc forms are external important characteristics of vacuum arc while plasma parameters are the internal important characteristics. Controlling on the change regularity of external and internal characteristics has been become an important field in vacuum arc. Researches on the forms of vacuum arc using high-speed digital camera CMOS and diagnosis of plasma parameters based on digital image processing CCD are put in this paper, and all these point out the direction of the further study of controlling theory.Application of digital image process is absolutely necessary to get information characteristics of vacuum arc form images. Firstly, image format and image precision are reviewed; secondly vacuum arc images are noisily filtered using median filter; histogram equalization is applied to enhancing details and maximizing the information content of the arc images; the edge points of the arc images have been detected using Canny operator; the images geometric characteristic and their perimeter are analyzed; and images gray contour line and their pseudo-color display are shown. At last, all these can provide some theoretic of capturing the information from vacuum arc images.To do researches on the form characteristics of vacuum arc, in this paper, combined with the vacuum chamber model, experimental set-up is designed to do researches on the characteristics of vacuum arc, including a de-mounted stainless steels chamber with two glass windows, high arc current which is supplied by C through L at a frequency adjusted to about 50Hz and measurement of voltage-ampere etc. A high-speed image collecting system using CMOS digital camera is arranged. Using this system, the whole igniting process of vacuum arc is researched and analyzed. Axial area spreading speed of vacuum arc is put forward in the end. The effect of gap distance, voltage degree between the captor and axial magnetic on the axial area change are analyzed in particular. In order to get the vacuum arc parameters from the images information, an arc parameters diagnostic system using high-resolution digital CCD camera is designed too. A diagnostic mathematical model on plasma parameters is built based on principle of temperature radiation measurement, combined with Abel inversion; radial distribution of electron density and temperature distribution are diagnosed.In the end, in order to prove the feasibility of the optical method, the plasma parameters are measured using Langmuir probe. Comparative and analytic researches on the results are got by three different ways.The aim of these researches is to improve the work performance and reliability of switching devices and finish the protection and control of the power supply system. This work is based on the design of VCB with multiple breaks and vacuum arc of high current in short-gap is studied. It is one part of the key-project of NSFC:"Arc plasma adjusting and controlling in metal vapor and its applications in the field of high voltage circuit breakers" (No.50537010). The related theoretical researches on the form characteristics and plasma parameters of vacuum switching arc are taken in this dissertation, some experimental basis for vacuum arc controlling theory have been put forward.更多还原