关键词: 微风振动, 加速度传感器, 希尔伯特-黄变换(HHT), 瞬时参数, 疲劳损伤

Abstract: In view of the errors caused by existing conductor vibration monitoring, which measures the conductor aeolian vibration with the average amplitude and frequency per second, this paper proposes an online monitoring and early warning technology for conductor aeolian vibration considering the transient characteristics of vibration. According to the positive piezoelectric effect of piezoelectric materials, a vibration monitoring sensor is designed to measure the acceleration time history curve of the point 89 mm away from the suspension clamp. In order to obtain the instantaneous amplitude and frequency, the intrinsic mode function (IMF) that conforms to the vibration mechanism of the original signals, is obtained using the empirical mode decomposition (EMD) combined with correlation judgment. The instantaneous parameters are extracted using Hilbert transform (HT), and the damage parameters of each element under dynamic bending stress are calculated using instantaneous amplitude and instantaneous frequency. The effectiveness of the proposed method is validated through numerical analysis. A comparative analysis is conducted with vibrating table test, and the results indicate that within the conductor’s effective damage frequency range of 0~60 Hz, the coincidence degree between the fatigue damage parameters obtained by test and the calculated values is more than 86.77%, and the maximum testing error of the main fatigue damage parameters n_i is 8.02% and the average testing error is 0.92%. The comparative analysis shows that the proposed method could provide an effective warning basis for the fatigue life of vibrating conductors.

Key words: aeolian vibration, acceleration sensor, Hilbert-Huang transform (HHT), instantaneous parameters, fatigue damage