GIS局部放电定位方法的研究本科毕业论文.doc

北方民族大学 学士学位论文 论文题目: GIS 局部放电定位方法的研究 摘 要 随着社会高速的发展，对电能质量的要求越来越高，同时对设备安全运行的要求也相应提高。GIS(气体绝缘封闭式组合电器)以其体积小，可靠性高等优点受到电力系统的欢迎。GIS从设计的出发点、是设计成不需维护的设备，然而，一旦GIS发生故障，其修复时间将更长，对电力系统的危害也更大。 局部放电是GIS中绝缘老化的一个最为重要的因素，目前已使用的在现场检测有检测放电产生的光，超声波，电流，电磁波等等，由于方法本身的缺陷或者检测后的处理问题加上现场强烈的干扰，使得检测精度不高。针对这种情况，本文采用紧贴在绝缘支撑物表面安装的外部天线检测GIS中局部放电产生的电磁波信号。重点对利用两天线的时间差进行局放点定位展开研究。试验证实，利用时间差可对局部放电源进行较为精确的定位。 文章首先介绍了局部放电危害以及目前的检测方法，接着介绍了检测系统的结构和试验方法，利用实验数据对放电点的定位，在比较的基础上得出最终论。 关键词: 局部放电 , GIS(气体绝缘封闭式组合电器), 在线监测, 时延估计 ABSTRACT Higher and higher quality electrical power supply is needed with the development of the society. So GIS has more and more applications in the power system due to its characteristics advantage,such as small volume,high quality,etc. Essentially,GIS is designed not to need maintenance. However in case of an insulation breakdown,it takes a longer time for its restoration and the breakdown causes more serious damage to system operation As is known to all.partial discharge is a symptom of an insulation breakdown occurring in GIS.So it is very important.At present,signals of light.supersonic wave.current and electromagnetic wave which are emitted from GIS can be utilized to determine whether PD occurs.however, The solve this problem,this paper proposes a noncontact detection method by using anatennas fitted closely on the outer circumference of the insulation space to receive signals of electromagnetic wave emitted. We emphasizes particularly on the research of using the time delay bewteen signal from two antennas to locate the PD in GIS. Experiments proved that the time delay between the signals can be use to find correctly the location of defects in GIS. This paper :The first part introduces basic knowledge such as PD's principle and detection methods used now . The second part introduces the system for detecting and our experiment.and the last part analyze the data to locate the defectsand gets the conclusion. Key words: PD GIS ,on-line mon