针对传统的FRA方法在信号源选择及分析手段上的局限性,改用脉冲信号和雷电脉冲代替正弦扫频信号,经试验验证,改进后的方法试验周期短,信号响应的频率范围更宽,拓宽了响应信号的低频范围和高频范围,增加信号分析可靠性和故障诊断的准确性;并在频率响应曲线分析的基础上增加了FFT和EMD分析方法。通过变压器绕组变形故障检测系统的构建与试验分析研究,结果表明该系统能较快检测变压器绕组变形故障,并判断出故障的类型,提高了绕组变形故障诊断的可靠性。
Regarding the limitation of signal source selecting and analyzing means,the impulse and lightning electromagnetic pulse(LEMP)are adopted to replace the sine frequency sweep signal.After the improvement,the test cycle is reduced and the signal frequency response range is broader as well as the response range of low frequency and high frequency is expanded,which increase the analysis accuracy and diagnose sensitivity.Then the FFT and EMD method is added based on the analysis of frequency response curves.Through the building and testing on the deformation fault diagnosis system of transformer winding,the analysis results shows that it can detect the fault of winding deformation rapidly and determine the type of faults,which enhance the accuracy and stability of transformer winding deformation diagnosis.