检测变压器故障的扫频阻抗法特性研究及应用  

Characteristics and Application of Sweep Frequency Impedance Method for Detecting Transformer Fault

作　　者：刘勇[1] 汲胜昌[1] 杨帆[1] 饶章权 柯春俊 杨贤 

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [2]广东电网有限责任公司电力科学研究院,广州510080

出　　处：《高电压技术》2016年第10期3237-3245,共9页High Voltage Engineering

基　　金：南方电网公司重大科技专项(K-GD2014-170)~~

摘　　要：为了更加有效地诊断变压器绕组变形,基于扫频阻抗(SFI)法的理论基础,在实验室内构建了一套绕组变形测试系统。以特制单相双绕组变压器为例,引入相关系数(CC)和短路阻抗(SCI)偏差作为判据,对正常和发生短路故障及翘曲故障的变压器进行了测量,并理论分析了故障后扫频阻抗曲线的变化情况。结果表明:扫频阻抗系统具有较高的测试重复性,其在相同测试条件下10次测试的相对标准偏差皆<0.35%,且该方法在频率为50 Hz处的阻抗值等效于该单相变压器的短路阻抗值;初始扫频阻抗曲线最大值与最小值相差约0.6 M?,不利于绕组故障的判断,需进行分贝化转换,经转换后扫频阻抗曲线跨度只为原来的0.1‰;单相变压器发生短路故障时,其扫频阻抗曲线会在最大波峰处产生较为明显的波谷;扫频阻抗法可利用短路阻抗法和频率响应分析(FRA)法判据对单相变压器故障进行判定。To diagnose the transformer winding deformation more effectively, a measurement system based on sweep frequency impedance（SFI） method was developed. It was applied on detecting short circuit and warping faults within a single phase transformer with two windings by the criteria of correlation coefficient（CC） and short circuit impedance（SCI）, and the changes of SFI curves obtained from faulty transformers were theoretically analyzed. The results show that the SFI measurement system has a high repeatability, the relative standard deviations from ten tests under the same measurement condition are all less than 0.35%, and the value of SFI curve at 50 Hz is basically equal to SCI value. The span value of the original SFI curve is about 0.6 M？, which is hard to judge whether the fault exists, but it is 0.1‰ of the original span value after being transformed into decibel. There is an obvious wave trough on the frequency point of the original wave peak, when short circuits fault exists. Besides, the criteria of frequency response analysis（FRA） and SCI can be used to diagnose the faults within a single transformer in SFI method.

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 单相变压器 相关系数 

分 类 号：TM407[电气工程—电器]