【作者】 张阔；

【导师】 李卫国； 唐赈；

【作者基本信息】 华北电力大学 ， 电气工程（专业学位）， 2013， 硕士

【摘要】 真空断路器广泛应用于中低压配电系统,用于控制和保护输电线路和用电设备。真空度是断路器最重要的参数,一旦灭弧室内真空度下降,将造成不能正常切断负载电流,将给电力系统和用户带来严重的灾难。为了研究真空断路器灭弧室内真空度与局部放电状态的关系,设计了一套模拟断路器运行环境实验平台,采用特高频方法测量了灭弧室内不同真空度下局部放电信号,并利用统计参数法统计出不同压强下局放信号特征参数。在此基础上通过对局部放电数据处理分析,得到不同压强下局部放电PRPD谱图,作为间接诊断断路器灭弧室真空度的依据。灭弧室局部放电改变了屏蔽罩的电位,屏蔽罩的电位随着局部放电的发生不在是平滑下降。通过搭建试验平台,测试真空断路器屏蔽罩的基波、谐波交流电位随着真空度变化而变化,基于试验结果提出了一种实用的真空度在线监测系统,能够实时发现运行中真空断路器遭破坏的程度,及时采取措施防止事故的发生。在线监测系统采集传感器信号,利用高阶数字滤波器分离传感器信号中的工频信号和高频信号。利用趋势算法、三相不对称算法、状态估计等算法对检测数据的综合分析,消除周围电磁环境带来的误差,准确判断断路器的真空度状态。最后通过RS485实现PC机和信号采集处理系统数据传输,实时上传数据分析结果。利用图像化编程语言LabVIEW开发上位机,实时显示监测系统的数据,同时也可以通过PC机发送指令对信号采集分析系统控制,对信号采集系统参数进行校准与分析,实现在线远程更新在线监测系统软件。更多还原

【Abstract】 Vacuum circuit breakers (VCBs) have operated successfully in medium voltage distribution system to control and protect power lines and power equipments. Inner pressure of vacuum interrupts (VI) is one of the most important parameters. Once the internal pressure In Arc Extinguish Chamber might increase, Ⅵs can’t cut off the load current normally. Heavy losses would be brought about to both the power system and the consumers. For the research of the relationship of vacuum degree in arc extinguish chamber and partial discharge, we designed a testing system which can simulate the running environment of arc extinguish chamber and use the UHF method to measure the partial discharge. On the basis of the experiment, we did some data processing and get PRPD graphs by the different vacuum which can be a very important basis to diagnose the vacuum degree of the arc extinguish chamber.Partial Discharge in arc extinguish chamber have changed the shielding potential. The shielding potential with partial discharge occurs is not smoothed down. Measure the fundamental, harmonic potential of the Ⅵ’s shield with the change of the vacuum degree change by making the test platform. Based on the experiment results we put forward a practical method of on-line monitoring vacuum degree. To take some ways to prevent the accidents through detecting operation of vacuum switch destruction.The system of on-line monitoring will collect sensor signals which are separated into power frequency signal and high frequency signal by using high order digital filter. The tendency to judge method, comprehensive diagnosis by three phase asymmetric algorithm, harmonic method and state estimation algorithm for detecting data can enhances the sensitivity and reliability of the system which will eliminate the error caused by the surrounding electromagnetic environment. Finally, the PC and the signal acquisition and processing system realize data transmission via RS485which can upload the results of data analysis in real time. The upper computer developed by the graphical programming language Lab VIEW is displaying the data of the system of on-line monitoring. But also to send instructions to the signal acquisition and analysis system of control, signal acquisition, system parameter calibration and analysis through PC machine, the program of the system can be updated by the remote PC.更多还原