电工技术学报2024，Vol.39Issue(1)：65-75,11.DOI:10.19595/j.cnki.1000-6753.tces.230738
电缆终端应力锥错位缺陷对界面温度及应力分布的影响
Influence of Cable Terminal Stress Cone Dislocation Defect on Interface Temperature and Stress Distribution
摘要
Abstract
As an important part of the prefabricated cable terminal,the stress cone structure can alleviate the concentration of the electric field strength at the cut-off of the insulation shielding layer during the operation of the cable terminal.However,in the installation and construction of the cable terminal,due to the influence of the installation process and operating conditions,the cable terminal will have a stress cone dislocation defect,which will affect the uniform distribution of the terminal electric field;at the same time,the increase in cable core and insulation temperature will lead to a change in the thermal stress distribution in the terminal and affect the thermal stress distribution in the terminal.At present,the research on cable terminal defects mainly focuses on electro thermal aspects,while there are few studies on their internal stress distribution.In this paper,the electro-thermal-mechanical multi-physical field coupling simulation analysis of the dislocation defect cable terminal is carried out to analyze the changes in electric field strength,temperature distribution,and stress distribution in the operation of terminal defects. During the operation of the cable terminal,the heat source is formed due to the electromagnetic loss,which leads to the change of the internal temperature of the terminal,and then the thermal stress and deformation of the terminal are generated by the thermal expansion of the material.Firstly,the physical field control equations of the cable terminal are established and the coupling relationship between the physical fields is analyzed.Then,the cable terminal model and the stress cone dislocation defect model are established,and the material parameters and boundary conditions are set and simulated.Finally,by comparing the maximum electric field strength,temperature change,and interface pressure distribution under the condition of a cable terminal defect,the influence of a stress cone dislocation defect on terminal temperature and stress is obtained,and suggestions are given for cable terminal installation,operation and maintenance. The simulation results show that when the cable terminal is in normal operation,the electric field strength of the insulation interface changes abruptly at the cut-off position of the shielding layer.The maximum temperature of the terminal cable core is 312 K,and the maximum thermal stress is 1.37×107 N/m2.The terminal interface temperature and interface pressure are abruptly changed at the cut-off position of the insulation shielding layer.When the installation size of the cable terminal is too small,the maximum electric field strength of the insulation interface is 2.25 MV/m,and the electric field rise zone appears between the cut-off of the insulation shielding layer and the root of the stress cone.When the dislocation size of the cable terminal is-7.5 mm,the temperature of the insulation interface reaches its highest value.When the terminal dislocation size is-2.5 mm,the insulation surface pressure value is the largest,reaching 3.78×105 N/m2.When the dislocation size of the cable terminal is +7.5 mm,the maximum electric field intensity of the insulation interface increases to 2.42 MV/m,and distortion occurs at the truncation of the insulation shielding layer.When the installation size of the terminal is too large,the sudden change in the interface temperature will increase,the pressure of the cable terminal on the insulation surface will increase,and the pressure of the insulation interface will be obviously distorted.When the dislocation size of the cable terminal is +5.0 mm,the insulation interface pressure reaches a maximum of 3.46×105 N/m2.According to the above conclusions,the dislocation defect of the cable terminal will seriously affect the stress distribution of the terminal and superimpose with the electric field and temperature field,resulting in terminal insulation damage and aging.Therefore,the design and installation of the cable terminal should pay attention to the occurrence of stress cone dislocation defects,especially to avoid the electric field distortion and stress distortion caused by the excessive installation size of the terminal.关键词
电缆终端/应力锥错位缺陷/电缆界面应力/电-热-力多物理场耦合Key words
Cable terminal/stress cone dislocation defect/cable interface stress/electro-thermal-mechanical multi-physics coupling分类
信息技术与安全科学引用本文复制引用
祝贺,何峻旭,郑亚松,曹煜锋,郭维..电缆终端应力锥错位缺陷对界面温度及应力分布的影响[J].电工技术学报,2024,39(1):65-75,11.基金项目
吉林省科技发展计划资助项目(20230203136SF). （20230203136SF）
