小波包分析在振动法监测变压器铁芯及绕组状况中的应用

THE APPLICATION OF THE WAVELET PACKET TO THE MONITORING OF THE CORE AND WINDING CONDITION OF TRANSFORMER

通过分析小波包的特性 ,提出了一种基于小波包分析得到变压器器身振动的能量特征矢量的方法 ,该特征矢量可作为变压器铁芯故障诊断的判据。在实验室中 ,进行了空载条件下变压器铁芯振动的测试。从时域的信号来看 ,故障后的振动加速度信号幅值比正常状况下有了一些变化 ,但难以形成确定的判据来衡量电力变压器发生故障程度的大小。对振动信号进行小波包分解 ,得到基于小波包分析的能量特征矢量 ,从实验结果可以看出这种方法可有效地判断铁芯是否存在故障。

In this paper,via analyzing the characteristic of WPT,a method of gaining the energy eigenvector of transformer tank vibration based on the wavelet packet is brought forward,the eigenvector can be used for monitoring the transformer core condition.At the lab,the vibration signals oftransformer' core at no load condition were tested.Compared to the normal condition,when the core has been at defect there were exiguous changes at the time domain,thus an affirmatory criterion can not been gained to assess the degree of the transformer' defect.The vibration signals were analyzed using WPT arithmetic and the energy eigenvectors were gained.From the result of experiment,we can see this method is very useful to estimate the condition of the transformer' core.