【作者】 郭俊；

【导师】 吴广宁；

【作者基本信息】 西南交通大学 ， 电力系统及其自动化， 2006， 硕士

【摘要】 高压储能电容器作为脉冲功率系统的核心储能元件,其绝缘性能直接关系到脉冲功率系统工作可靠性。现有电容器的检测手段仅限于测试其电容值、介质损耗,或是充放电次数,这些参数一方面不能在电容器出厂时检测出产品的某些内在缺陷;另一方面不能对服役期间电容器的绝缘老化状况进行评估。近年来,局部放电作为反映绝缘内在缺陷的表征参数被广泛采用,因此也适用于丰富电容器出厂检测和服役期性能评估手段。但是,以往的局部放电测量大都是在工频条件下,对于小电容量试样而进行的,对于高压储能电容器,原有的检测方式存在着测试灵敏度不够、分析手段不足等缺点。 论文主要针对建立适用于大电容试样的直流局部放电测试系统而开展工作。从局部放电原理出发,以噪声分析为基础,设计出一套灵敏度高、噪声抑制比强的直流局部放电测试系统;为使每次测量具有可比性,按照IEC60270标准设计局部放电校准仪;针对不同缺陷类型的电容器试样进行直流局部放电试验,验证了系统的可靠性。最后,在比较各种常用数字滤波技术的基础上,采用小波变换技术作为去除直流局部放电信号干扰的有力工具,并比较得出最适合本系统的基小波函数。 本论文的研究工作可用于高压电容器的出厂试验及其运行中的性能检测,对改善制作工艺以及用户检测设备性能都具有实际意义。同时,本论文的工作也是研究直流下局部放电产生发展规律的基础。更多还原

【Abstract】 The insulation capability of High Voltage Storage Capacitor (HVSC), which is the kernel of impulse power, determines the service reliability of impulse power system. In nowadays, only capacitance, dielectric loss or discharge times are counted as characteristics of capacitors. These parameters, a) can’t find out the failure inside when it comes out of manufacturer;b) can’t evaluate the capacitors when they’re in service. However, Partial Discharge (PD), which is widely used as a parameter of inside failure in insulation, is considered that it should be useful in capacitor. But, almost all the PD tests are based on power frequency and low capacitance sample, whose sensitivity, analysis methods etc. are not suitable for HVSC.This thesis works on the DC PD detection system which is designed for HVSC specially. First, the thesis starts off PD mechanism, and analyses the noise and its source. Then, a high sensitivity and noise rejection DC PD detection system is designed. And, in order to make every test comparable, a PD calibration system was decided. This system is validated though a series of test. At last, wavelet transfer is selected as powerful digital filter after compared with others.All the work the thesis introduced can be used in HVSC factory detection and in service performance check, and it’s useful for manufacturer to improve their craft or check their equipments. At the same time, it’s also the basic of further PD research on the patterns how discharge developed.更多还原