直埋电缆的暂态温升特性及波动负荷输送能力研究  

Study on Transient Thermal Response and Fluctuating Load Transmission Capability of Power Cables Buried in Earth

作　　者：但京民 李文清 崔戎舰 刘英[2] 李健 吴高波 DAN Jingmin;LI Wenqing;CUI Rongjian;LIU Ying;LI Jian;WU Gaobo(Central Southern China Electric Power Design Institute Co.,Ltd.,of China Power Engineering Consulting Group,Wuhan 430071,China;School of Electrical Engineering,Xi′an Jiaotong University,Xi′an 710049,China)

机构地区：[1]中国电力工程顾问集团中南电力设计院有限公司,武汉430071 [2]西安交通大学电气工程学院,西安710049

出　　处：《电线电缆》2023年第6期34-41,共8页Wire & Cable

基　　金：中国能源建设集团规划设计有限公司科技项目(GSKJ2-D03-2021)。

摘　　要：介绍了梯形等效热路模型的建立方法,给出了分层确定损耗、热阻、热容等参数,并计算外加任意负荷下电缆暂态温升的分析流程,以单芯电缆在阶跃负荷下的温升特性为例,验证了模型及程序的有效性。在此基础上,针对三芯海缆结构提出了基于热阻相等原则的等效方案,并以330 kV 3×1000 mm^(2)电缆为例,在典型风电场波动负荷作用下,研究了电缆温度随时间的变化特性,程序计算结果与有限元仿真数据一致。研究表明,直埋电缆热时间常数大,具备良好的短时过载及波动过载能力;利用等效热路模型及程序算法可确定单芯及多芯电缆的暂态热场响应特性,从而为应用于如风电场这类波动负荷传输的电缆实际负载能力评估提供技术依据,优化了电缆选型及参数设计。Establishment principle of equivalent trapezoidal thermal circuit model of a cable was explained,the method to divide insulation and soil into layers and to determine parameters such as loss,thermal resistance and thermal capacity was given,and the procedure to calculate cable transient temperature rise under arbitrary loads was presented.Then,the model and the program were verified by a case on a single-core cable,whose temperature rise under a step load current was simulated.Based on it,an equivalent scheme with a principle of equal thermal resistance was proposed for three-core cables,and by taking a 330 kV 3×1000 mm^(2) submarine cable as the example,temperature change curves under typical fluctuating loads of wind farms were calculated,with a good consistency with FEA simulation results.It was shown that thermal time constant of a directly buried cable was large,providing a good endurance for short-term or fluctuating overload current.The equivalent thermal circuit model and program algorithm could be used to assess the transient thermal response of single and multi-core cables,and to evaluate cable transmission capacity for fluctuating loads such as in wind farms,which was important for the optimization of cable selection and parameter design.

关 键 词：直埋电缆 梯形等效热路 波动负荷 暂态温升特性 选型优化 

分 类 号：TM247[一般工业技术—材料科学与工程]