【作者】 李岩松；

【导师】 刘云鹏；

【作者基本信息】 华北电力大学 ， 电气工程（专业学位）， 2015， 硕士

【摘要】 气体绝缘开关设备(Gas Insulated Switchgear,GIS)由于结构紧凑,占地面积小,易于维护等优点,在电力系统中得到了广泛应用。G I S一旦出现故障,有可能导致大面积停电,对国民经济造成巨大损失。因此,对GIS内部局部放电进行检测,及时、准确的发现早期绝缘故障,对于保障GIS安全运行和提高供电可靠性具有重要意义。针对目前GIS局部放电检测中存在的问题,本文结合光电转换技术、光纤传输技术、数字信号处理技术以及虚拟仪器技术,研制出了一套基于光纤传输的GIS局部放电超声波检测系统。研制了基于光纤传输的GIS局部放电检测硬件系统。设计放大滤波电路提高了采集信号的信噪比,在准确提取放电信号的基础上有效剔除干扰信号;远端采集模块采用光脉冲同步触发信号解决了GIS局部放电检测中多路信号的同步采集问题;采用光纤通信系统传送采集的数字信号,抗干扰能力强,实现了信号的准确传输和强电侧、弱电侧的电气隔离;通过UDP协议实现上、下位机数据的发送与接收,提高了系统的扩展能力。基于Lab VIEW虚拟仪器技术开发了与硬件系统对应的软件系统和人机交互界面。设计实现了数据采集、数据处理、数据存储、数据查询等功能。数据采集模块通过UDP网络功能协议实现采集数据的通信;数据处理模块通过小波分析对采集到的超声波信号进行滤波处理,结合门槛阈值的设定实现对局部放电数据的提取。在实验室搭建了GIS局部放电试验平台,运用本套系统对GIS运行中常见的四种典型故障进行了检测,得到了不同缺陷模型的典型放电特征。利用分形理论计算得到不同缺陷模型的分形参数,运用模糊C均值算法对特征值进行聚类识别。结果表明,运用所提取的分形参数结合模糊C均值算法可以良好的识别四类典型缺陷模型放电,为GIS局部放电的模式识别提供了一种新的方法。依托国家“863计划”科研项目,运用本套系统对西安、石家庄、保定等地多个变电站的GIS设备局部放电进行了现场检测,发现了多处局部放电故障。试验研究和现场应用均验证了本套系统的有效性。更多还原

【Abstract】 Gas Insulated Switchgear (GIS) is widely used in power system for its compact structure, small footprint and easy to maintain. It could lead to large area blackout and huge losses to the national economy once GIS fails. So internal partial discharge (PD) detection of GIS insulation faults timely is significantly important to guaranteeing safety and reliability of GIS. Aiming at existing problems in GIS PD detection, a set of GIS PD ultrasonic detection system based on optical fiber transmission is designed, combined with photoelectric conversion technology, optical fiber transmission technology, digital signal processing technology and virtual instrument technology.A set of GIS PD detection hardware system based on optical fiber transmission is developed. Amplifying and filtering circuit designed in the paper effectively improved the SNR of collected signal and removed interfering signal on the basis of extracting discharge signals accurately. The remote collection module adopting optical pulse synchronization trigger signal solved simultaneous acquisition problem of multiple signals problem. Digital signal transmitted through optical fiber communication systems with high anti-interference ability realized accurate signal transmission and electrical isolation of high-voltage side and low high-voltage side. The system realized data sending and receiving between host computer and lower computer by UDP-protocol, and improved the expansion capability.The corresponding software system to hardware system and interactive interface were developed based on LabVIEW virtual instrument technology. The system can realize data acquisition, data processing, data storage, data query, etc. The data acquisition module realized data communication by UDP network protocol. The data processing module can realize filtering processing of collected ultrasonic signals by wavelet analysis and extracts the partial discharge data by threshold setting.The GIS partial discharge test platform is set up, by which four kinds of typical defects in GIS operation were detected, and then got typical discharge characteristics of different defect models. Using fractal theory, fractal parameters of different defect model were calculated, and the parameters are applied to clustering recognition as characteristic quantity by fuzzy C-means. The results show that the use of extracted fractal parameters combined with fuzzy C-means algorithm can recognize four types of discharge defects effectively, which is a new method for pattern recognition for GIS PD.Relying on the national 863 scientific research project, the author conducted a series of site detection of GIS PD in substations of Xi’an, Shijiazhuang and Baoding, and found several PD defects. Experimental research and site applications have verified the effectiveness of the system.更多还原