考虑互热影响的直埋电缆温度场解析计算  

Analytical Calculation of Temperature Field of Buried Cable Considering Mutual Thermal Effect

作　　者：于坤生 庞丹 齐明泽 鲁志伟[1] YU Kunsheng;PANG Dan;QI Mingze;LU Zhiwei(Electrical Engineering College,Northeast Electric Power University,Jilin Jilin 132012;Changchun Power Supply Bureau of Jilin Power Grid Co.Ltd,Changchun Jilin 130000)

机构地区：[1]东北电力大学电气工程学院,吉林吉林132012 [2]国网吉林省电力公司长春供电公司,吉林长春130000

出　　处：《东北电力大学学报》2022年第2期85-91,共7页Journal of Northeast Electric Power University

基　　金：国家科技部重大项目(2018YFB0904600)。

摘　　要：IEC标准求解直埋电缆暂态温升时,土壤部分温升采用指数积分公式计算,电缆部分则采用热路模型,求解导体温升需要对电缆和土壤分别分析,增加了计算的复杂性.电缆间的互热效应及土壤对电缆温度场的影响可通过土壤热路模型模拟,与电缆部分的热路模型结合形成完整的RC热路模型.首先根据标准中给出的求解公式计算模型中各层的热阻、热容、热源,然后以有限元法求得的电缆温度场为基准,验证了新模型在稳态及暂态计算时的准确性,最后将模型应用于实际工程计算中.结果表明:当电缆集群敷设时,新模型可正确模拟电缆群的稳态温度分布;计算电缆暂态温升时,与有限元仿真结果相比,解析法的最大误差为3.2℃,平均绝对值误差在0.57℃之内.新模型的误差在工程允许范围内,可用来快速计算电缆周围存在热源时的温度分布.When IEC standard is used to solve transient temperature rise, the soil part adopts the exponential integral formula, while the cable part adopts the heat path model.When analyzing the temperature rise of conductor, the cable and soil need to be analyzed separately, which increases the complexity of calculation.In this paper, the mutual thermal effect and soil influence between cables are classified into the soil thermal path model, and the RC thermal circuit model is formed by combining with the model of cable part.Firstly, the thermal resistance, heat capacity and heat source of each layer in the model are calculated according to the formula given in the standard.Then, the accuracy of the new model in steady state and transient calculation is verified based on the cable temperature field obtained by the finite element method.Finally, the model is applied to the actual engineering calculation.The results show that the new model can simulate the steady-state temperature distribution of cable group correctly when the cable cluster is laid.When calculating the real-time temperature of cable, the maximum error of analytical method is 3.2 ℃ and the average absolute error is within 0.57 ℃ compared with the finite element simulation results.The error of the new model is within the allowable range of engineering, and can be used to calculate the temperature field of the cable when there is heat source.

关 键 词：电缆温度场 RC热路模型 互热效应 有限元仿真 

分 类 号：TM247[一般工业技术—材料科学与工程]