Research on Vibration Analysis and Online Monitoring Technology of Transmission Tower Near Railway

The transmission line is the key facility of power grid systems all over the world. The transmission tower is an important part of the transmission line. Vibration response analysis can be applied to structural health monitoring, since environmental factors and external excitation will have a certain impact on the accuracy of mode. Tower 126 of the Xinjiang Guangfang line is close to the train track, and external excitation will be generated when the train passes, so it is important to study the influence of the train on the tower. This study conducts dynamic response experiments on the transmission tower. To identify the modal parameters of the tower under different states, an automatic modal identification method of the tower is used to process the vibration acceleration signal. It is found that train excitation will stimulate high order modes. The tower mode will decrease as the train passes, and the third and eighth natural frequencies change obviously. The influence of train excitation on the mode of transmission tower leads to the misjudgment of the structural health of the transmission tower by the monitoring device. After the train passes through the transmission tower, if the tower is not permanently damaged due to train excitation, the structure can still be restored to its original state after a certain time. Therefore, the authors design and optimize the vibration monitoring device of the Guangfang line tower to avoid power safety accidents.