摘要
为了明确不同金属屏蔽形式对高压直流电缆载流量的影响,并对比热分析法和有限元仿真两种理论计算方法结果的准确性,选取导体截面3 000 mm2的铜芯±525 kV交联聚乙烯(XLPE)绝缘直流电缆,分别通过热分析法和有限元仿真计算皱纹铝套和铜丝屏蔽结构下直流电缆的载流量,并设计直流载流试验对两种电缆样品进行载流量测试。结果表明:相同条件下铜丝屏蔽结构电缆载流量大于皱纹铝套结构,但是两种载流量的理论计算结果均小于试验结果,且存在明显偏差。基于热分析法计算得到的铜丝屏蔽结构电缆在空气中28℃条件下的载流量为2842A,对比有限元仿真结果和试验结果分别偏小7.5%和15.8%;基于热分析法计算得到的相同条件下皱纹铝套结构电缆载流量为2 836 A,对比有限元仿真结果和试验结果分别偏小5.3%和8.6%。造成热分析法计算结果偏小的主要原因在于其仅考虑电缆热传导过程中的热阻影响,无法计算外部空气对流产生的热辐射对载流量的提高,且无法考量电缆结构内部空气对热传导的作用;有限元仿真计算方式在热传导作用之外还具备识别热辐射作用的能力,计算结果更为接近试验结果,差异来源主要为该文所建立的模型未准确表征电缆实际存在的空气隙和皱纹铝套结构,此外有限元仿真计算无法准确模拟实际试验时空气对流产生的电缆表面散热情况。
To clarify the influence of different metallic screen types on the current rating capacity of HVDC cables, and to compare the accuracy of calculation results of thermal analysis and finite element simulation, we selected ±525 kV XLPE insulated cables with copper conductor cross-section of 3 000 mm2 as examples to perform the experiments. The current rating capacity of HVDC cable with copper wires and corrugated aluminium sheath were calculated based on thermal analysis and finite element simulation respectively, then the results were verified by DC current loading tests. The calculation results show that the current rating capacity of HVDC cable with copper wires is greater than that with corrugated aluminium sheath under the same condition. But the results based on two calculation methods above are both smaller than those of loading tests, and also obvious deviations exist. Based on thermal analysis, the current rating capacity of ±525 kV cable with copper wires is 2 842 A under 28 ℃ in air, which decreases by a 7.5% compared to the result of finite element simulation and decreases by 15.8% compared to the result of DC current loading tests, respectively. Under the same condition, the current rating capacity of ±525 k V cable with corrugated aluminium sheath is 2 836 A based on thermal analysis, which decreases by 5.3% compared to the result of finite element simulation and decreases by 8.6% compared to the result of DC current loading test, respectively. The reason is that, in the thermal analysis, only the influence of thermal resistance in the process of cable heat conduction is taken into consideration, but the increase of heat radiation of external air convection to current rating capacity can not be calculated, and also the effect of air on heat transfer inside the cable structure is not taken into consideration. Due to the ability to recognize thermal radiation effects in addition to heat conduction, the calculation results based on finite element simulation are more close to test results. However, t
作者
张洪亮
尹毅
谢书鸿
胡明
范玉军
李星辰
ZHANG Hongliang;YIN Yi;XIE Shuhong;HU Ming;FAN Yujun;LI Xingchen(Department of Electrical Engineering,School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education,Shanghai 200240,China;Zhongtian Technology Submarine Cable Co.,Ltd.,Nantong 226010,China;Shanghai National Center of Testing and Inspection for Electric Cable and Wire Co.,Ltd.,Shanghai 200093,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2021年第6期2117-2123,共7页
High Voltage Engineering
基金
国家重点研发计划(2016YFB0900703)
江苏省重点研发计划(BE2018090)。
关键词
高压直流电缆
热分析法
有限元仿真
载流量计算
载流量试验
HVDC cable
thermal analysis
finite element simulation
current rating capacity calculation
current rating capacity testing
