A research on the influence of antivibration hammer displacement on the vibration characteristics of transmission lines based on SSI-COV

The transmission line will be damaged by various factors in the exposed external environment. Although the deployment of the anti-vibration hammer on the transmission line has a certain protective effect, after a long period of vibration, the anti-vibration hammer will loosen and cause displacement, which will affect the vibration characteristics of the line. Therefore, in order to detect the influence of anti-vibration hammer displacement on the vibration characteristics of transmission lines, firstly, the vibration acceleration signals of transmission lines without anti-vibration hammer, 20 cm displacement of anti-vibration hammer, 150 cm displacement of anti-vibration hammer and 300 cm displacement of anti-vibration hammer are measured by experiments. Secondly, the least mean square (LMS)adaptive filtering is performed on the acceleration signal to make the waveform complete and smooth. Thirdly, the natural frequency of the wire is extracted based on the covariance random subspace method (SSI-COV ), and the data of the four working conditions are compared and analyzed. Finally, a total of 11 order natural frequency values are obtained by SSI-COV stability diagram. The experimental results show that the first order natural frequency of the wire changes the most, the second and third order natural frequencies show an obvious increasing trend, and the last several order frequency values do not change significantly with the distance away from the position of the damper. Therefore, the position of the anti-vibration hammer can be further analyzed by using the first-order natural frequency value in practical engineering.