三芯电缆不平衡电流对温度分布的影响  

Influence of Unbalanced Current in 3-core Power Cable on Temperature Distribution

作　　者：阮羚 赵艾萱[3] 邓丹 杨波 杨帆 邓军波 张冠军[3] RUAN Ling;ZHAO Aixuan;DENG Dan;YANG Bo;YANG Fan;DENG Junbo;ZHANG Guanjun(State Grid Hubei Electric Power Research Institute,Wuhan 430077,China;Key Laboratory of High-Voltage Field-Test Technique,State Grid Corporation of China,Wuhan 430077,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi＇an Jiaotong University,Xi＇an 710049,China;Xianning Power Supply Company State Grid Hubei Electric Power Company,Xianning 437000,China;Wuhan Power Supply Company,State Grid Hubei Electric Power Company,Wuhan 430077,China)

机构地区：[1]国网湖北省电力公司电力科学研究院,武汉430077 [2]国家电网公司高压电气设备现场试验技术重点实验室,武汉430077 [3]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [4]国网湖北省电力公司咸宁供电公司,咸宁437000 [5]国网湖北省电力公司武汉供电公司,武汉430077

出　　处：《高电压技术》2018年第8期2704-2709,共6页High Voltage Engineering

基　　金：国网湖北省电力公司科技项目(52153214001K);国家自然科学基金(51577150);国家自然科学基金创新研究群体科学基金(51521065)~~

摘　　要：在三芯配电电缆的实际运行过程中,由于各相上的用户负荷需求并不一致,通常存在三相电流不平衡的情况,因此亟需准确评估不平衡电流下的电缆温升情况。现有IEC 60287等关于电缆载流量的标准均按照三相平衡情况进行考虑,本文采用有限元法,建立了排管敷设下电缆温度场计算模型,并对A相设置不同的不平衡度,利用二分法计算了相应不平衡度下B、C相的最高负荷电流。结果显示：不平衡度偏离零值越高时,在90℃下电缆能够输送的总电流越小,而不平衡度为0.6时整体损耗最低。因此在配网运维管理中可根据情况,利用实际存在的不平衡度有效掌握线损率,提高设备资产利用率。When 3-core distribution power cable is in service, unbalanced current in 3-phase usually occurs due to the different demands of consumers load in different phases. As a result, it is necessary to determine the cable temperature rise under unbalanced current. Only balanced conditions of 3-phase current are considered in IEC 60287 and the thermal circuit method is too difficult to calculate temperature rise. Therefore, we applied a finite element method to build a numerical model for cables＇ thermal field. Using the cable thermal field model, we set different unbalanced degrees in phase-A and calculated the greatest load current of phases-B and phases-C by dichotomy. According to the results, if the further unbalanced degree deviates from 0 value, the total current of cable transmitting under 90 ℃ is less. Besides, the total loss of cable is smallest when the unbalanced degree is 0.6. Distribution administrator can make use of different unbalanced degrees to decrease the line loss rate and increase the cable utilization ratio.

关 键 词：三芯电缆 有限元法 不平衡电流 载流量 温度分布 

分 类 号：TM75[电气工程—电力系统及自动化]