检测电力变压器绕组变形的扫频阻抗法研究  

Study on Sweep Frequency Impedance to Detect Winding Deformation Within Power Transformer

作　　者：刘勇[1] 杨帆[1] 张凡[1] 朱叶叶 汲胜昌[1] 孙翔[2] 傅晨钊[3] 

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049 [2]国网浙江省电力公司电力科学研究院,浙江省杭州市310014 [3]国网上海市电力公司电力科学研究院,上海市虹口区200437

出　　处：《中国电机工程学报》2015年第17期4505-4516,共12页Proceedings of the CSEE

基　　金：国网浙江省电力公司科技项目(5211011306X9)~~

摘　　要：为了有效诊断变压器绕组变形,该文提出一种新型变压器状态检测方法——扫频阻抗法,并基于其基本理论,建立了一套变压器绕组变形测试系统,在深入探讨该测试系统的性能后,对正常和发生短路故障及局部凹陷故障的变压器进行了测量,理论分析了发生故障后的扫频阻抗曲线变化情况。结果表明:扫频阻抗系统具有较高的测试重复性与稳定性,且其50 Hz处的阻抗值基本等于额定短路阻抗;较高的激励电压能够有效抑制空间噪声干扰;扫频阻抗曲线比频响曲线更为稳定和平滑,且在中高频段时两者呈现轴对称关系;绕组发生短路及凹陷故障的扫频阻抗曲线的差异极为明显,证明了扫频阻抗法用于变压器绕组变形检测的可行性。最后通过现场测试,验证了扫频阻抗法的有效性。To diagnose transformer winding deformation effectively, this paper presented a new testing technique named sweep frequency impedance （SFI） for the detection of transformer condition, and a measurement system was developed based on this new method. After the research on the performance of the testing system, the reasons leading to changes of SFI curves on transformer winding faults （short cricuit and local dent） were explained through academic analysis. The results show that： 1） The SFI measurement system has a high repeatability and stability, and the value of SFI curve at 50Hz is basically equal to sweep frequency impedance （SCI） value. 2） The input signal with higher voltage level can reduce influence of spatial noise effectively. 3） The SFI curve is more stable and smoother than the frequency response analysis （FRA） curve, and the relationship between SFI and FRA curves tends towards axial symmetry at medium-high frequency band. 4） Due to the obvious difference of the changes of SFI curves between short circuit and local dent faults, it is viable that SFI measurement is used to detect transformer winding deformation. Moreover, onsite result proves that the SFI is an effective method to detect winding deformation of a power transformer.

关 键 词：变压器绕组变形 扫频阻抗法 短路阻抗法 频率响应分析法 现场测试 

分 类 号：TM855[电气工程—高电压与绝缘技术]