摘要
氧化锌避雷器，简称MOA，由氧化锌非线性电阻}MOv)组成，是目前常温下理想的过电压保护装置。超导技术是21世纪具有战略意义的高新技术，极具发展潜力的市场前景和巨大的市场利益使各国对其给予高度重视，并大力支持超导技术的研发和加速其产业化进程，超导脉冲功率也在发展过程中。为了探讨MOV在低温下的应用前景，论文在研究MOV低温电气特性的基础上，探讨其在超导脉冲功率方面的应用。
论文首先研究了MOV在低温C 77K)下小电流区的交直流电气特性，接着探讨了MOV在低温下的大电流振荡冲击和雷电波冲击情况下的电气特性，并分别与常温下的试验数据进行了对比分析，明确了其应用十低温环境中的关键参数、性能。论文还对MOV在超导磁体产生的强脉冲电流冲击下的冲击特性和破坏特性进行了分析，最后几章着重论述MOV在脉冲功率方面的应用研究。具体做了以下几方面的工作:
(1)研究了一种高精度的数据拟合方法一洛推法，并进行了数学分析和试验数据验 证，为探讨MOV在小电流区的交流特性提供了分析方法。
(2)研究了小波分析在冲击测量数据分析中的应用，通过大量的数据分析，验证了小波分析可实现高压或大电流冲击试验领域的脉冲和振荡信号的提取，为分析MOV的冲击特性打下基础。
（3)试验研究了低温下MOV在小电流区的交直流电气特性，以及大电流冲击特性和 雷电冲击特性，并与常温下相应的数据进行了对比分析，试验分析结果表明:MOV在低温下的吸能特性、残压等方面都优十常温下相应的特性，ifu b_低温下 MOV的冲击响应速度很快，基本没有延迟效应，这些都说明MOV能很好工作在 低温环境中。
（4)提出了超导脉冲磁体的内部保护的一种方法，并进行了相应仿真分析和部分试 验验证，仿真和试验结果表明:MOV与磁体线饼并联可以有效地限制磁体的过电压，并目_能作为超导脉冲磁体内部的泄能电阻，快速释放能量。
（5)试验研究了高温超导磁体对低压MOV直接放电的电气特性，重点探讨了超导磁体对MOV产生的破坏效应，为改进MOV的配方和探索其在超导线圈保护方面的应用提供了基础数据。
(6)在深入研究高温超导磁体放电的基础上，将仿真和试验相结合，探讨了MOV作为脉冲成形电阻的优缺点。
（7)基十超导脉冲成形的仿真分析和试验研究，设计了基十高温超导磁储能的脉冲 成形装置，并进行仿真分析验证。其中MOV作为保护兀件对超导磁体和超导脉冲变压器的线饼(圈)进行过电压保护，防止释放能量时烧毁超导线饼(圈)，同日寸保护用的MOV可以减少因为开关动作对输出波形的影响。
关键词:MOV，非线性，内部保护，过电压高温，超导，脉冲成形，脉冲成形电阻 超导磁体
Abstract
The Metal Oxide Arrestor (MOA), composed of metal oxide varistor (MOV), is a perfect protector for over-voltage. The superconducting technology is a promising topic in the development of electrical engineering in the 21 st century, which will greatly change the power industry, can also be used in pulse power technology. However, protective technology under low temperature is fundamental for superconducting technology and pulse power technology. If MOV is used for protection or else in low temperature,
characteristics of MOV in low temperature must be studied.
In this paper, the author firstly studied AC/DC characteristics of MOV in low current regions, and analyzed characteristics of MOV under pulse which produced by impulse oscillating generator and lightning generator, and then the author compared the results at liquid nitrogen temperature (77K) with the corresponding results that got from normal
temperature. Based on these results from the above experiments, the author put forward the protective scheme of high temperature superconductive (HTS) magnet using MOV, and brought forward other application about MOV in HTS pulse power technology. The paper mainly contains seven contents as follow:
(1)Analyzed and proved the Method of Synthesizing Vector(MSV) in order to deal with datum that got from experiments in low current regions;
(2)Discussed the application of filter technique based on wavelet transformation in impulse wave evaluation, by using this method, noise signals were drawn out from
signals of impulse experiments.
(3)Analyzed AC/DC characteristics of MOV in low current regions, and discussed characteristics of MOV under pulse which produced by impulse oscillating and lightning surge experiments, then compared the results at liquid nitrogen temperature with the corresponding results that got from normal temperature. Results show that at liquid nitrogen temperature some characteristics of MOV, i.e. absorbing ability residual voltage, are better than normal temperature. Some characteristics of some type of MOV at liquid nitrogen temperature, e.g. non-linear and brittleness are worse than normal temperature. In another hand, feedback speed of MOV is so swift that we can even ignore the delay, and above all indicates protective character of MOV under pulse is good at liquid nitrogen temperature
(4)Put forward selection method using MOV for HTS pulse magnets inner protection, analyzed and proved the method by experiments and simulink analysis.
(5)Discussed microstructure change of MOV after it was destroyed by pulse which was released by HTS magnet, and analyzed the destroyed theory of MOV under this pulse then put forward the advice about MOV's amelioration when it was applied in HTS magnet protection.
(6)Based on the discharge experiment of a small HTS magnet, put forward a pulse form network (PFN), then analyzes and proves the method by experiments.
(7)Based on the electromagnetic characteristics of MOV and HTS magnet, a PFN based on HTS pulse magnet and transformer was designed, thereinto, MOV is a protector for the HTS pulse magnet and transformer, and it can also sharp the output wave.
Key words: Metal Oxide Varistor (MOV) Non-linear Inner protection Over volatge High temperature superconductor (HTS) Pulse form network (PFN) Pulse form HTS magnet
目录
摘要
ABSTRACT
1绪论
1.1引言
1.2 MOV的研究现状
1.3超导及超导脉冲功率技术的研究现状
1.4论文研究的内容和创新点
2低温下MOV的小电流特性研究
2.1引言
2.2 MOV的小电流特性的试验分析方法
2.3低温下MOV在小电流区的特性研究
2.4本章小结
3低温下MOV的大电流脉冲冲击特性研究
3.1引言
3.2振荡电流发生装置介绍
3.3试验数据分析方法
3.4低温下MOV的冲击特性探讨
3.5本章小结
4低温下MOV的雷电冲击特性研究
4.1引言
4.2电压型雷电冲击装置
4.3试验方法
4.4试验数据分析
4.5试验结论
4.6本章小结
5 MOV用做超导磁体内部保护理论和试验研究
5.1引言
5.2超导磁体的保护方案
5.3超导磁体放电试验
5.4 MOV的损坏分析
5.5本章小结
6 MOV在超导磁体脉冲功率成形中的应用探讨
6.1引言
6.2高温超导磁体储能特性
6.3试验用高温超导磁体设计
6.4高温超导磁体放电特性研究
6.5超导磁体脉冲输出回路探讨
6.6 MOV应用于超导磁体输出回路的试验探讨
6.7综合回路设计及其分析
6.8本章小结
7全文总结
7.1全文总结
7.2后续工作要点
致谢
参考文献
