基于灵敏度法的三芯电缆线芯温度影响因素分析  

Analysis of the Temperature Affecting Factors of Three-Cores Cable Core Based on Sensitivity Method

作　　者：王鹏[1] 刘刚[1] 

机构地区：[1]华南理工大学电力学院,广东广州510640

出　　处：《电线电缆》2015年第4期14-19,29,共7页Wire & Cable

摘　　要：为了动态提高三芯电缆的实时载流量以及保证电缆安全稳定运行,对影响三芯电缆线芯温度的两个主要因素进行了分析,通过利用生物学中局部灵敏度的概念,分析了环境热阻与环境温度对三芯电缆线芯温度的影响。同时,搭建了10 k V三芯电缆载流量试验场,并模拟了空气敷设和土壤敷设下的三芯电缆温升试验。理论分析与实验结果可得:空气敷设时,随着加载电流的增大,环境热阻对电缆线芯温度的灵敏度增加,且都处于灵敏等级;土壤敷设时,环境热阻对电缆线芯温度的灵敏度处于不灵敏等级;同一加载电流下,外界环境热阻的变化对于电缆线芯温度的影响很大。两种不同敷设情况下,当三芯电缆线芯温度相等时,相比空气敷设情况,加载电流为200 A,土壤敷设时,电缆载流量可以提高3.6%;加载电流为300 A,土壤敷设时,电缆载流量可以提高8.1%;加载电流为400 A,土壤敷设时,电缆载流量可以提高9.2%;加载电流为500 A,土壤敷设时,电缆载流量可以提高22.3%。当三芯电缆运行状态未达到稳定时,电缆线芯温度主要由加载电流的大小决定;当三芯电缆运行状态达到稳定时,电缆线芯温度的变化趋势与环境温度变化趋势基本相同,线芯温度由敷设环境温度决定。In order to improve real-time current carrying capacity of three-core cable dynamicly and ensure the cable can operate safely and steadily,this paper analyzes two main factors that affect the temperature of three core cable core,and the effect of environmental resistance and environmental temperature on the temperature of three-core cable by using the concept of local sensitivity. At the same time,we set up the 10 k V three-core cable ampacity test field,and simulate three-core cable temperature rise test considering air and soil laying. From the theoretical analysis and the experimental results,we can obtain that: when considering the air laying,with the increase of loading current,the sensitivity of environmental resistance on the temperature of cable core will increase correspondingly,and they are all in sensitive level; On the other hand,when considering the soil laying. The sensitivity of environmental thermal resistance on temperature of cable core is not in sensitive level; The change of thermal resistance of external environment has great influence on the temperature of cable core under the same loading current. under the above different laying conditions,When the temperature of the three-core cable is equal,if the loading current is 200 A,carrying capacity can increase by 3. 6% in soil laying; If the loading current is 300 A,carrying capacity can increase by8. 1%;If the loading current is 400 A,carrying capacity can increase by 9. 2%; If the loading current is 500 A,carrying capacity can increase by 22. 3%; If the three-core cable doesn't operate stably,the temperature of cable core is determined by loading current; On the contrary,the temperature change tendency of cable core is basically the same as the temperature change tendency of environment,and the wire core temperature is determined by the laying ambient temperature.

关 键 词：三芯电缆 局部灵敏度 环境热阻 环境温度 线芯温度 

分 类 号：TM757[电气工程—电力系统及自动化]