基于时频变换的变压器绕组振荡波信号分析方法

Analysis Method of Transformer Winding Oscillation Wave Signal Based on Time-Frequency Conversion

为能进一步提高变压器绕组状态检测的可靠性,本文提出一种高压直流作用下通过开关切换产生的暂态激励获得绕组振荡波来分析绕组状态的方法。基于现场试验,本文通过连续小波变换对振荡波信号进行去噪,并分析其时频特性,通过引入图像识别方法与总矩阵相似度量化时频信号特征。结果表明:该方法测试效率高,矩阵相似度可较好反映不同幅值、不同输出侧下振荡波的重复性和规律性,并能较好反映变压器相间绕组的差异性,为研究变压器绕组变形检测提供了参考。

In order to further improve the reliability of transformer winding state detection,this paper presents a method to analyze winding state by using winding oscillation wave under HVDC transient excitation.Based on field experiments,this paper denoises the oscillating wave signal by continuous wavelet transform,and analyses its time-frequency characteristics.By introducing image recognition method and total matrix similarity,the time-frequency signal characteristics are measured.The results show that the method has high testing efficiency,and the matrix similarity can reflect the repeatability and regularity of oscillation waves under different amplitudes and output sides,and can better reflect the difference of transformer windings between phases,which provides a reference for the study of transformer winding deformation detection.