基于NICS脉冲信号注入法的变压器绕组变形在线监测装置研究  

Research on an Online Monitoring Device for Transformer Winding Deformation Using NICS Pulse Injection Method

作　　者：张重远[1] 王彦波[1] 张林康 张欣[1] 

机构地区：[1]华北电力大学河北省输变电设备安全防御重点实验室,保定071003

出　　处：《高电压技术》2015年第7期2259-2267,共9页High Voltage Engineering

基　　金：国家自然科学基金(50977031);中央高校基本科研业务费专项资金(09MG06)~~

摘　　要：电力变压器匝间故障将导致绝缘击穿,甚至造成整个电网事故的发生,为此,应用在线频率响应分析法检测变压器绕组变形。通过安装于变压器套管表面的非侵入式电容传感器（NICS）将测试信号通过高压套管注入变压器绕组从而实现了绕组变形的在线监测。开发了基于脉冲信号注入法的变压器绕组变形在线监测系统。着重阐述了测试信号的选择,在线信号的注入,保护电路的设计。分析了信号源和采样频率对频响特性测试结果的影响。对一台型号为35 k VA/10 k V/400 V的配电变压器进行测试,并与安捷伦频谱网络分析仪4395A的测试结果进行对比发现,在0~5 MHz频率范围内,两条频响曲线的相关系数为0.955 3。结果表明,该系统能在在线状态下准确、快速地获取变压器绕组数10 MHz内的频响特性。监测系统具有较高的灵敏度和重复性,能有效检测变压器绕组变形。Interturn faults in power transformers can lead to insulation breakdown, even result in an overall network failure, thus we used the on-line frequency response analysis （FRA） to detect deformation and displacement Of windings in power transformers. A test signal was injected into the transformer windings through a noninvasive capacitor sensor （NICS） installed on the surface of the transformer bushing, so as to realize online monitoring of transformer windings. We developed a test system by the impulse response analysis, and elaborated the main difficulties of system development in- cluding test signal selection, online signal injection, and the design of the protection circuit. Key factors of signal source and sampling rate affecting FRA measurements are also analyzed. Finally, we carried out an experiment on a 10 kV/400 V, 35 kVA oil-immersed distribution transformer in the laboratory, and compared the measurement results with results by Agilent spectrum network analyzers 4395A, and the correlation coefficient of the two frequency response curves is 0.955 3 in the frequency range between 0 and 5 MHz. It is proved that the system is able to obtain the frequency response of transformer windings up to tens of 10 MHz accurately and rapidly, which verifies that the system has higher sensitivity and reproducibility and can effectively detect the deformation of transformer windings.

关 键 词：变压器 NICS 纳秒脉冲发生器 绕组变形 频率响应分析法 在线监测 

分 类 号：TM41[电气工程—电器]