Modal parameters identification of power transformer winding based on Hilbert-Huang Transform

Modal parameters are inherent properties of power transformer winding and closely related to its variations of mechanical condition. To identify the modal parameter of winding more accurately, a modal experiment on a real transformer winding is made in this paper and the vibration frequency function is obtained. Then Hilbert-Huang Transform is introduced to identify the winding modal parameters from the experiment data. The general frequency-domain method PolyMax is also used to extract modal parameters of the winding as a comparison to the proposed method. The first four ranks of modal parameters of the winding are obtained by proposed method and PolyMax method. The good agreements of two methods illustrate the effectiveness of proposed HHT method. Furthermore, the proposed HHT method has better accuracy on the identification of damping ratio of transformer winding. The results can provide theoretical foundation for transformer manufacturing and winding deformation detection based on vibration.