Research on key parameter identification method for structural damage in ACSR conductors based on WPVMD

Abstract Since Aluminum Conductor Steel Reinforced (ACSR) is subjected to prolonged and non-uniform wind-induced vibrations, its vibration signals exhibit continuous forced vibration responses. Consequently, modal information is often obscured by noise, posing significant challenges for the modal identification of transmission lines. To address this issue, this paper proposes a Wavelet Packet Variational Mode Decomposition (WPVMD)-based method for identifying key structural damage parameters in ACSR conductors. By incorporating an energy entropy threshold and an empirical threshold for wavelet packet node denoising, the method reconstructs joint signals to extract modal parameters. This approach not only enhances the identification of modal information buried in noise but also effectively eliminates the influence of forced vibrations. The effectiveness of the proposed method is validated through finite element simulations of transmission lines. Additionally, it is applied to the modal parameter identification of a laboratory-based conductor vibration platform. The results demonstrate that the method successfully corrects pseudo-peaks in conductor vibrations, suppresses external interference, and extracts free vibration responses from transmission conductors. These findings highlight its potential application in the structural health monitoring of transmission lines.lines.