±500kV直流海缆在J型管敷设环境下的稳态载流量仿真研究  

Simulation Study on Steady-state Ampacity of ±500kV DC Submarine Cable Under J-tube Laying Environment

作　　者：夏源 赵学童[1] 冯勇 侯帅 冯宾 XIA Yuan;ZHAO Xuetong;FENG Yong;HOU Shuai;FENG Bin(State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University),Shapingba District,Chongqing 400044,China;Electric Power Research Institute China Southern Power Grid,Guangzhou 510663,Guangdong Province,China)

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044 [2]南方电网科学研究院有限责任公司,广东省广州市510663

出　　处：《中国电机工程学报》2023年第12期4851-4860,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51877016);重庆市自然科学基金项目(cstc2019jcyjxfkxX0008);教育部霍英东教育基金项目(171050)。

摘　　要：高压直流海底电缆稳态载流量的计算对海底电缆工程的设计和运行非常关键。该文利用COMSOLMultiphysics仿真软件,建立±500kV直流海底电缆在J型管敷设环境下的三维电-热-流耦合模型。针对J型管位于海面之下和海面之上2种情况,分别计算海缆的稳态载流量、温度分布以及电场分布。结果表明,J型管海缆运行在海面之下时载流量比运行在海面之上高约2倍。此外,发现海缆绝缘中的电场分布取决于绝缘内外层的温度差,当绝缘层内、外表面温差等于6.0℃时,整个绝缘层电场均匀分布,大小为16.7kV/mm;当绝缘层内、外表面温差大于6.0℃时,海缆绝缘电场分布沿电缆径向由内向外逐渐增大;当温差小于6.0℃,绝缘电场分布沿电缆径向由内向外逐渐增小。另外,减小J型管壁厚和增大J型管外径可以在一定程度上提升海缆的稳态载流量,对运行在海面之上的J型管内电缆施加通风冷却可将其稳态载流量提升约73%。The calculation of steady-state ampacity of HVDC submarine cable is of great significance to the design and operation of submarine cable.A three-dimensional electric-thermal-fluid coupling model of 500kV DC±submarine cable under the J-tube laying environment is established using COMSOL Multiphysics software.For the two cases that the J-tube is located below and above the sea surface,the steady-state ampacity,temperature distribution and electric field distribution of submarine cable under different conditions are calculated,respectively.The results show that the steady-state ampacity of submarine cable running below the sea surface is about two times higher than that running above the sea surface.It is also found that the electric field distribution in submarine cable insulation depends on the temperature difference between inner and outer insulation layers.When the temperature difference from inner surface to outer surface of the insulation layer is equal to 6.0℃,the field strength is uniformly distributed in the submarine cable insulation and keeps at a constant value of 16.7kV/mm.As the temperature difference goes higher than 6.0℃,the field strength shows an increasing trend from inner surface to outer surface of the insulation layer along the radial direction.While the temperature difference is below 6.0℃,the field strength shows a decreasing trend from inner surface to outer surface of the insulation layer.Moreover,it is found that the steady-state ampacity of the submarine cable can be improved slightly by reducing the thickness of J-tube wall and increasing the external diameter of J-tube.It is proposed that the steady-state ampacity can be boosted by about 73%by forced-air cooling to the J-tube running above the sea surface.

关 键 词：直流海缆 稳态载流量 J型管 有限元法 

分 类 号：TM247[一般工业技术—材料科学与工程]