# Dynamic Simulation of Underground Cable Laying for Digital Three-Dimensional Transmission Lines
## 1 Introduction  
With the development of the economy and the improvement of people's living standards, the demand for power facilities and electricity continues to increase, so related power construction is also continuously strengthened [1]. Among them, during the laying of high-voltage cables, if the cables withstand excessive traction or lateral pressure, it may cause deformation and damage to the cables, which will affect their service life and thus affect the safe and stable operation of the power grid [2]. During construction, it is common for cables to be deformed due to excessive stress on the laid cables. There are many factors affecting the safe laying of cables. Due to the limitations of actual conditions, it is impossible to implement specific real model tests, so we can only rely on manualcalculations to obtain basic data. The actual construction process often relies more on past experience and judgment.  
Because it is common for cables to be deformed due to excessive stress during cable laying, cable laying construction methods have received widespread attention. [PERSON] and others [3] established a transmission line tension stringing system model through the secondary development of the virtual prototype ADAMS, realizing the real-time dynamic display process of conductors and traction ropes during the tension stringing process. [PERSON] and others [4] studied the influence of the traction plate on the contact force of the conductor and pulley when passing through the pulley by analyzing the axial speed and tension changes of the conductor and traction rope based on the simulation model of the stringing system. [PERSON] and others [5] proposed a laser point cloud-based method for simulating the construction process of tension paying out of transmission lines. [PERSON] and others [6] clarified the issues that should be paid attention to in terms of checking driving force and side pressure, traction method, and radius of curvature when hauling cables by the windlass, and improved the traction system to ensure cable laying standards. Using three-dimensional software, [PERSON] et al. [7] established a cable laying model for each interval distribution unit, completed a three-dimensional visualization simulation of cable laying at a station, accurately designed the cable laying path, and formed a cable laying optimization design scheme with smooth cable connection and economic savings.  
However, the above studies are all aimed at the simulation research of the tension-stringing system of transmission lines and the calculation and monitoring of traction force during cable laying. In recent years, cable lines have shown a rapid development trend [8], and a dynamic simulation of the cable laying system is currently still missing [9]. Therefore, this paper proposes a digital-based cable-laying construction process simulation method to solve the problem that the cable-laying construction of transmission lines mainly relies on drawings and cannot intuitively feel the safety hazards in the laying process and the contact collision between pulleys and cables. Simulating the dynamic process of cable laying on the construction site, analyzing the error between the axial tension of the cable and the laying speed and the theoretical calculation value, and finally analyzing the axial tension of the cable and the bearing capacity of the pulley to effectively control the construction process and explore safety, provides important data support for accurate cable construction. The mean error between the real value and the simulation value is 2.75%. We find that the method proposed in this paper is accurate and reliable compared with other methods.