Nan'ao ±160 kV multi-terminal flexible DC power transmission project uses the high-voltage and large-length extruded insulated DC cable system firstly in China,while there is no operation and maintenance experience of 160 kV DC cable project at present.In order to provide technical support for the customization of the online monitoring system and the control of operational limits,it's necessary to study the ampacity characteristics of DC XLPE cable.Through the study of the cooling principle of DC cable in different laying environment,the thermal field model of ± 160 kV DC XLPE submarine cable with protective tubes laying underground is established by using the professional finite element software COMSOL Multiphysics,to simulated the temperature distribution and calculate the ampacity.The cable load flow tests are carried out in the test site to verify the reliability of the simulation model,whose results are discussed to obtain the ampacity characteristics of DC submarine cables.%南澳岛±160 kV多端柔性直流输电工程在我国首次采用了高电压、大长度的挤包绝缘直流电缆系统,而目前在国内尚无此电压等级直流电缆工程的运行及维护经验,因此亟需对交联聚乙烯(XLPE)直流电缆的载流特性展开研究,从而为直流电缆线路运行限值的控制以及在线监测系统的定制提供技术支持.通过研究不同敷设环境下直流电缆的散热原理,采用专业有限元软件COMSOL Multiphysics建立了带保护套管埋地敷设方式下±160 kV直流XLPE海底电缆的温度场模型,用以模拟其温度分布和计算其载流量;通过在试验场地开展静态载流试验,对仿真模型的可靠性进行了验证;对试验结果进行讨论,分析得出了直流海缆的载流特性.
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