Modal parameter calculation and vibration characteristic analysis of transmission line conductor

Abstract

Structural damage identification technology based on modal parameters is an extremely effective monitoring method. Because of the structural characteristics of the conductor, with its small diameter and long span, it is not easy to obtain the modal parameters by manual excitation. Here, a method for structural health monitoring of the conductor under wind load excitation is proposed. Firstly, the natural frequency change law of the conductor after broken strand damage is obtained by analyzing the conductor modal parameters calculation formula and IEEE standards. Then, the vibration characteristics are calculated by vibration experiments and finite element methods. Finally, through the broken strand experiment, this paper demonstrates how to determine the damage degree of the conductor using the modal parameters. And it is applied to online monitoring in the field. The results show that this method is convenient, fast, and accurate.

Research on online monitoring method for time-varying tension in transmission lines based on operational modal response

“…In order to ensure a longer service life after the installation of the sensors, two power supply methods are used: inductive energy harvesting and lithium battery power supply. Compared to traditional wired sensors and wireless sensors used for short-term inspections, this equipment has a relatively large weight, which has a certain impact on the modal characteristics of the wire [28]. Therefore, a modal correction method is needed to remove the influence of the acceleration sensors on the wire itself.…”

“…The IF curves in the target process are accurate, smooth, and continuous, providing a basis for evaluating the instantaneous tension of the wire. As a comparison, the time-frequency spectra obtained using the currently more advanced Fast Synchro-squeezing Transform (FSST) algorithm [28] are shown in figure 8(a). The frequency resolution is reflected by the width of the frequency domain stripes in the figure, with narrower stripes indicating higher resolution.…”