通过测量直流下局部放电可剔除有绝缘缺陷的电容器以保证脉冲功率系统的可靠性。为此根据实际制造过程中绝缘缺陷状况设计了高压脉冲储能电容器的缺陷模型并定制了含有人工缺陷的电容器。研制了相应的直流局放测试系统。该测试系统的数据采集系统中利用Delta(t)方法把交流下局部放电的统计分析方法引入到直流电容器下的测量过程,且利用高速数据采集卡的触发采集功能捕捉局部放电的脉冲形状,大大将低了局部放电高速数据采集的冗余数据。电容器直流局部放电测试分析系统基于客户/服务器(C/S)模式构建。集数据的采集、上传、下载、分析功能于一体,通过在C/S模式中引入关系数据库,解决了直流局部放电高速数据采集和有限数据存储能力的矛盾,且达到了多人共享统计分析局部放电数据的目的。对含人工缺陷电容器的测试结果证明测试系统满足预定的要求。
According to the defects condition in the process of manufacture, defect models of capacitor are designed and capacitors that has manual defect are made. In this paper, Delta (tl method is presented, so AC partial discharge statistic and analysis method can be used in DC condition. Because there is no phase window in DC detection, redundant data in DC partial discharge digital detection can be generated. To solve this problem, a trigger data collection method is used in the process of DC partial discharge detection. Data acquisition card starts working only when partial discharge pulse appears, so only partial discharge pulse data are collected in the process of detection. There is little redundant data in the detection result and the load of digital detection system can be reduced. Through the use of SQL Server 2000 relational data base, the problem of high sample frequency but limit ability of data storage is resolved and the partial discharge data can be easily shared by the group in this analysis system. Partial discharge detection and analysis system is designed based on a C/S mode, and the system has the function including data collection, data upload, data download and data analysis. At last, the partial discharge of internal defect capacitor is detected, and its 2D statistic figure and SD statistic figure are presented.