Modal Parameters Identification of Transformer Winding Based on Analytical Wavelet Transform

Modal parameters of power transformer winding are closely related to vibration feature,dynamic optimal design and fault diagnosis of the winding structure.Considering the difficulty of obtaining the accurate modal parameters of the power transformer winding,an axial excitation experiment of a 10 kV power transformer was made in the paper.The complex wavelet transform was introduced and applied to the analysis of the measured vibration signal.Then,algorithm of Crazy Climber was employed to extract the wavelet ridge,and the first three natural frequencies and the damping ratio of the transformer winding were obtained.The results from this method were found to be in good agreement with those calculated by the identification method of Poly MAX in frequency domain.It shows that the proposed method is correct and effective.Furthermore,it is shown that the proposed method has strong anti-interference feature and can be applied effectively to the identification of the modal parameters of transformer winding.