Finite Element Analysis Of The Influence Of Thermal Expansion And Abrasion Conditions On The Mechanical Properties Of High Voltage Cables

High voltage cables are an important equipment to ensure power system transmission and data communication,its normal operation plays an important role in social and economic development.Land cables are laid under three typical types:snake-shaped laying,pipe laying and bending laying,and the conductors work for a long time under the maximum ampacity load.The conductor generates huge thermomechanical force which may cause the damage.The submarine cable will be partially exposed under the washing of the ocean current,and it will easily be abraded with the rocks and damaged.Based on the thermodynamic theory,the paper determines the heat exchange method of the temperature field for different laying conditions of the land cable.The land cable under the serpentine laying and bending laying is exposed in the air.The model built in this paper mainly considers the internal heat conduction and air convection heat transfer of the land cable.This paper adopts a direct coupling method for thermal structure modeling,that is,applying temperature load and structural load to the model at the same time.In this paper,heat radiation is considered when establishing the thermo mechanical model for laying pipes.This paper uses indirect coupling to model the thermal structure of the land cable laid by the pipe.First,the temperature field distribution of the land cable is solved,and then the obtained temperature field is applied as a load to the analysis of the structure.In this paper,a thermomechanical finite element model for land cable bending is established and solved,and the deformed data is extracted.The electric field of the insulating layer is modeled,and the influence of thermal expansion on the electric field of the insulation under different bending radii is analyzed.In addition,based on the transient dynamics theory in the finite element method and the actual operating conditions of the submarine cable,this paper uses ANSYS to set the contact pair between the cable and the rock,apply the load,and establish and solve the cable wear model.In this paper,the distribution characteristics of temperature field,displacement,stress and strain of land cables under snake-shaped laying and pipe laying are obtained.The electric field distortion of the insulation layer of land cables under different bending radii is obtained.The stress and strain distribution characteristics of the submarine cable under the scour of the ocean current and the abrasion of the rock and the vibration characteristics of the optical unit are obtained.The research in thispaper provides a theoretical basis for the laying and daily monitoring of high-voltage cables.