基于电—热场耦合分析的高压大容量直流XLPE海缆绝缘结构研究

Research on Insulation Structure of High Voltage and Large Capacity DC XLPE Submarine Cable Based on Electric⁃thermal Field Coupling Analysis

随着交联聚乙烯直流海缆向着高电压、大容量的方向发展,其在工程应用中也遇到了温度和电场两方面的挑战。文中结合±160 kV XLPE直流海缆建立了XLPE海缆的电场仿真模型和热路模型,对更高电压等级的XLPE直流海缆的结构特点进行了探讨。通过仿真发现,直流海缆绝缘层的厚度同时影响海缆的温度和场强分布,在对高电压、大容量海缆设计时需要综合考虑绝缘材料能承受的最大场强和最高温度,选取合适的绝缘层厚度。同时,通过仿真对比铜、铝导体电缆对电场、温度的影响发现,铜导体电缆运行温度较低,有利于电缆稳定运行,而铝导体海缆虽然体积更大,但其重量小,更有利于安装敷设。

With the development of XLPE DC submarine cables towards high voltage and large capacity,it encoun⁃ters the challenges in such two aspects as temperature and electric field in engineering application.In this paper,the electric field simulation model and thermal circuit model of the XLPE submarine cable are set up in combination with±160 kV XLPE DC submarine cable,and the structural characteristics of XLPE DC submarine cable with high⁃er voltage is discussed.It is found through simulation that the thickness of the insulation layer of the DC submarine cable affects both the temperature and the field strength distribution of the submarine cable.In the case of designing a high⁃voltage and large⁃capacity submarine cable,it is necessary to comprehensively consider the maximum field strength and the maximum temperature that the insulation material can withstand and to select the most appropriate thickness of the insulating layer.At the same time,it is also found through the simulation and comparison of the ef⁃fects of cables with copper and aluminum conductor on the electrical field and temperature that the operation tem⁃perature of cable with copper conductor is lower and is beneficial to the stable operation of cable.While,the subma⁃rine cable with aluminum conductor,despite of its large volume,has small weight and is more beneficial for the in⁃stallation and laying.