GIS沿面放电模型和外置UHF传感器的研制

发布时间：2018-01-24 19:40

本文关键词： 气体绝缘组合电器特高频局部放电沿面放电浇注孔传感器　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来气体绝缘组合电器(Gas Insulated Switchgear,GIS)局部放电特高频(Ultra High Frequency,UHF)检测技术以其灵敏度高、抗干扰能力强、有效检测范围大、可进行故障定位和模式识别等优点在我国得到了大力发展和广泛应用。本文从局部放电模型、UHF电磁波通过GIS绝缘子上浇注孔的传播特性以及外置式UHF传感器的研制开发三个方面对局部放电特高频检测技术进行了深入研究,旨在为GIS局部放电检测系统的标准化以及标定系统的建立解决一些重要技术难题并提供相应的技术支持。本文在深入分析GIS内部沿面放电机理的基础上提出了一种结构独特的放电模型,即“针-球”沿面放电模型,通过实验室空气环境下的测试和在实际GIS中SF6气体环境下的测试,证明了该沿面放电模型具有放电量小、放电稳定、可重复性好和动态范围较大(低气压下)等优点。当前关于UHF电磁波传播特性的研究主要集中在GIS腔体,而关于浇注孔对UHF信号的影响则少有关注。本文通过实验和仿真两种手段,得出了浇注孔的尺寸与其辐射出的电磁波信号强度的关系:浇注孔表面的电场强度方向与其短边的方向平行;浇注孔表面辐射出的信号强度与其长边长度密切相关,与短边长度关系不大;浇注孔表面辐射出的信号强度随其长边长度的增加会先增加,而后的变化趋势与具体的放电类型有关:对沿面放电,其辐射出的信号强度随长边长度增加不断增强;对尖刺放电和自由金属颗粒放电,辐射出的信号强度在长边长度为75mm时达到最大。本文以UHF电磁波通过浇注孔的传播特性为依据,研制出了3种UHF传感器:蝶形缝隙天线、半椭圆型天线和半圆形天线。通过仿真求取了其驻波比、方向图、远场增益和等效高度曲线等技术参数,结果表明三种天线均满足设计要求。利用这三种UHF传感器在开放自由空间内和GIS平台上的两项实验表明半椭圆型天线和半圆形天线的时、频域性能均明显优于两种已获得入网许可的UHF传感器,可以在局部放电UHF检测领域推广应用。
[Abstract]:In recent years, Gas Insulated switch gis (Gas Insulated switch gis) partial discharge ultra high frequency (UHF) High Frequency has been developed. The detection technology of UHF has high sensitivity, strong anti-interference ability and wide range of effective detection. The advantages of fault location and pattern recognition have been developed and widely used in China. The propagation characteristics of UHF electromagnetic wave through the pouring hole on the GIS insulator and the research and development of the external UHF sensor are studied in this paper. The purpose of this paper is to solve some important technical problems and provide corresponding technical support for the standardization of GIS partial discharge detection system and the establishment of calibration system. Based on the in-depth analysis of the internal discharge mechanism of GIS. A discharge model with unique structure is proposed. That is, the "needle-ball" side discharge model, through the test in the laboratory air environment and the SF6 gas environment in the actual GIS, it is proved that the discharge along the surface discharge model is small and the discharge is stable. The advantages of good repeatability and large dynamic range (at low pressure). The current research on the propagation characteristics of UHF electromagnetic wave is mainly focused on the GIS cavity. However, little attention has been paid to the effect of pouring holes on UHF signal. The relationship between the size of the pouring hole and the electromagnetic wave signal intensity emitted by the pouring hole is obtained: the direction of the electric field intensity on the surface of the pouring hole is parallel to the direction of the short side of the pouring hole; The intensity of the signal radiated from the surface of the pouring hole is closely related to the length of the long edge, but not to the length of the short edge. The signal intensity emitted from the surface of the pouring hole will first increase with the increase of the length of the long side, and then the variation trend is related to the specific discharge type: discharge along the surface. The intensity of the radiated signal increases with the length of the long edge. For spike discharge and free metal particle discharge, the radiated signal intensity reaches the maximum when the length of the long side is 75mm. This paper is based on the characteristics of UHF electromagnetic wave propagating through the pouring hole. Three kinds of UHF sensors, such as butterfly slot antenna, semi-elliptical antenna and semicircular antenna, are developed. The technical parameters such as standing wave ratio, pattern, far-field gain and equivalent height curve are obtained by simulation. The results show that the three kinds of antennas meet the design requirements. Using the three kinds of UHF sensors in open free space and on the GIS platform two experiments show the time of semi-elliptical antenna and semi-circular antenna. The performance of frequency domain is obviously superior to that of two kinds of UHF sensors which have been approved to enter the network. They can be widely used in the field of partial discharge (PD) UHF detection.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM595;TP212

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