电力电缆暂态热路模型中绝缘层的优化  

Optimization on the Insulating Layer of Transient Thermal Circuit Model of Power Cable

作　　者：刘刚[1] 王鹏宇[1] 周凡[1,2] 刘毅刚 LIU Gang1, WANG Pengyu1 , ZHOU Fan1,2, LIU Yigang3(1. Institute of Electric Power, South China University of Technology, Guangzhou 510640, China; 2. Yichun Power Supply Company, State Grid Jiangxi Electric Power Company, Yichun 336000, China; Special Committee of Cable, Guangdong Society For Electrical Engineering, Guangzhou 510080, Chin)

机构地区：[1]华南理工大学电力学院,广州510640 [2]国网江西省电力公司宜春供电公司,宜春336000 [3]广东电机工程学会电缆专委会,广州510080

出　　处：《高电压技术》2018年第5期1549-1556,共8页High Voltage Engineering

基　　金：国家高技术研究发展计划(863计划)(2015 AA050201)~~

摘　　要：为实现电力电缆导体温度在线监测的工程应用,研究了影响电缆传热的重要部分—绝缘层。首先对电缆暂态热路模型的构建、绝缘层的分层进行了论证与分析,然后分别构建了绝缘层等厚度、等热容、热容比、厚度比这4种分层方式下的热路模型,并实现了对导体温度的求解,最后以电缆载流温升实验进行了验证。结果表明：不同分层方式下导体温度计算值的绝对误差标准差？θ均受制于电缆绝缘的分层数,？θ随分层数的增加而明显下降,分层数由5层增加为30层时？θ平均下降0.5℃;但在分层数达到一定数量后,它对？θ的影响减小,分层数由30层增加为100层时？θ平均下降值低于0.1℃;在分层数较小时,绝缘层依据热容比和等厚度分层时对应的？θ稍低于其余2种方式,当分层数为5层时按照这2种方法建模的？θ比其余2种方法低0.1℃,而分层数达到20层以上时,4种方法的？θ将趋于一致。这对于电缆导体温度实时监测进而掌握其载流量有显著意义。To achieve the engineering applications of power cable conductor temperature online monitoring, the insulating layer, which is an important part of influencing cable heat transferring, is researched. Firstly, we established a transient circuit model of the cable and and analyzed the stratification of the insulation. Then, we constructed the transient circuit model under four hierarchical methods of the insulating layer, i.e. the equal thickness, the equal heat capacity, the heat capacity ratio and the thickness ratio, respectively, and realized the solution of the conductor temperature. Finally, the cable temperature rise experiments were carried out to verify the analysis of the appeal. The results show that the absolute error standard deviation of conductor temperature calculated values（i.e. ？θ） under different hierarchical methods is affected by the number of layers of cable insulation, and ？θ is obviously decreased with the increase of stratification. When the number of layers increases from 5 to 30, the average decline in value of ？θ is 0.5 ℃. After stratification reaches a certain number, increasing the number of layers has little effect on ？θ. When the number of layers increases from 30 to 100 the average decline in value of ？θ is lower than 0.1 ℃ and the number of subdivision does not play the governing role in the accuracy of the model at this time. When the number of layers is small, the insulation layer according to the heat capacity ratio and equal thickness of the corresponding ？θ is slightly lower than other two ways. When the number of layers is 5, ？θ of the models constructed according to these two methods is 0.1 ℃ lower than the other two ways. If the number of layers reaches 20, ？θ of four methods will tend to be uniform. It is meaningful to the real-time monitoring of cable conductor temperature and current.

关 键 词：电力电缆 暂态热路模型 绝缘层 分层数 计算误差 电缆载流量 实时监测 

分 类 号：TM247[一般工业技术—材料科学与工程]