摘要
交流电缆改为直流运行对于新能源发电并网以及提高供电容量有着重要意义.以35 kV交流交联聚乙烯(cross-linked polyethylene,XLPE)电缆为研究对象,采用有限元方法对三线双极式、单极式和双极式3种直流拓扑结构下的三芯交流电缆进行温度场仿真;同时考虑配电网中常见的影响因素,如靠近热水管道、电缆集群敷设、电流不平衡等,研究其对交流电缆改为直流运行下的电缆载流量的影响.研究发现:在相同工作温度下,35 kV交流XLPE电缆在单极式直流拓扑结构下运行时的载流量最小,在三线双极式直流拓扑下运行时的载流量最大;当交流电缆与城市供水管道水平间距为2.0 m,垂直间距为0.5 m时,在上述3种直流拓扑下运行时的载流量下降了约3.0%;在电缆集群敷设时,加载非同步峰值能使载流量最大提升90 A;电缆载流量随电流不平衡度先增大后减小,在不平衡度为0时,电缆载流量达到最大.研究结果为35 kV交流XLPE电缆的直流改造提供了参考依据.
Converting alternating current(AC)cables into direct current(DC)operation is of great significance to achieve new energy generation connected to the grid and increase power supply capacity.A 35 kV AC crosslinked polyethylene(XLPE)cable was taken as the research object,and temperature field simulation of the three-core AC cable was carried out through the finite element method under three kinds of DC topologies:three-wire bipole,monopole,and bipole.At the same time,common influencing factors in the distribution network were considered,such as distance from hot water pipes,cable cluster laying,and current imbalance,so as to explore the influence of these factors on the ampacity of the cable when the AC cable was changed to the DC operation.The results show that under the same operating temperature,the 35 kV AC XLPE cable has the smallest ampacity when operating under the monopolar DC topology and the largest ampacity under the three-wire bipolar DC topology.When the horizontal distance between AC cable and urban water supply pipes is 2.0 m,and the vertical distance is 0.5 m,the ampacity of cables operating under the above kinds of DC topologies is reduced by about 3.0%.The maximum ampacity can be increased by 90 A as the asynchronous peak value is loaded when the cable cluster is laid.The cable ampacity increases first and then decreases with increasing current imbalance,and it reaches the maximum value when the current imbalance is 0.The research results can provide some reference for converting 35 kV AC XLPE cables into DC operation.
作者
张添胤
王启隆
王新
金泱
杨敏
陈向荣
ZHANG Tianyin;WANG Qilong;WANG Xin;JIN Yang;YANG Min;CHEN Xiangrong(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China;ZJU-Hangzhou Global Scientific and Technological Innovation Center,Hangzhou 311200,China;Zhejiang Provincial Key Laboratory of High-Efficiency Energy-Saving and Pollutant Control Technology for Thermal Power Generation,Zhejiang Energy Research Institute Co.,Ltd.,Hangzhou 311121,China;Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices,Zhejiang University,Hangzhou 311200,China;International Research Center for Advanced Electrical Engineering,Zhejiang University,Haining 314400,China)
出处
《西南交通大学学报》
EI
CSCD
北大核心
2024年第6期1285-1293,1304,共10页
Journal of Southwest Jiaotong University
基金
浙江浙能技术研究院有限公司科技项目(JSYJY-SCFW-2022-009)
浙江大学“百人计划”(自然科学A类)的资助。