高压单芯电缆铝护套下热阻的动态特性与实验研究  

Dynamic Characteristic and Experimental Study on Thermal Resistance in Aluminum Sheath of High Voltage Single-core Cable

作　　者：刘刚[1] 周凡[1] 刘毅刚[2] 

机构地区：[1]华南理工大学电力学院,广州510640 [2]广东电网公司广州供电局输电部,广州510310

出　　处：《高电压技术》2013年第3期712-718,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB7-24507)~~

摘　　要：为了掌握电缆铝护套至导体热阻随温度变化的规律,提出了电缆铝护套至导体热阻的模型,通过高压单芯电缆阶跃电流温升实验,得到电缆各层在不同稳态下的温度分布,并根据热阻定义,推导电缆各层在不同温度下的热阻值及其随温度变化的规律。结果表明:电缆铝护套至导体热阻随温度的升高而降低,递减速率随温度的升高而变缓,并趋于稳定;单位长度电缆的绝缘层热阻和铝护套至导体热阻分别趋近于0.50 K.m/W和0.55K.m/W,其值比IEC 60287标准计算值分别小0.054 7K.m/W和0.077 1K.m/W;求得铝护套至导体热阻率为3.070K.m/W,比标准值小0.43K.m/W;气隙层热阻值为空气强制对流热阻值和接触热阻值并联之和,其值比标准值小1个数量级。To obtain the law of thermal resistance between aluminum sheath and conductor of cable（Ts-c） varying with temperature,we proposed and experimentally studied a model of Ts-c.Temperature distribution of cable layers in different steady states was obtained in step current temperature experiments on high-voltage single-core cable.Then,the thermal resistance of cable layers at different temperatures and their varying principles with temperature were deduced based on the definition of thermal resistance.The results show that Ts-c decreases with increasing temperature,at a rate that also decreases with increasing temperature,and tends to be steady at last.The thermal resistance of the insulation layer and Ts-c become to 0.50 K · m/W and 0.55 K · m/W,respectively,which are 0.054 7 K · m/W and 0.077 1 K · m/W less than their calculated values according to Standard IEC 60287,respectively.The experimental value of thermal resistivity between aluminum sheath and conductor is 3.070 K · m/W,0.43 K · m/W less than its standard value.The thermal resistance of air-gap layer is sum of air resistance and contact resistance,of which the order of magnitude is less than its standard value.

关 键 词：高压单芯电缆 热阻模型 热阻率 材料热阻 接触热阻 动态特性 

分 类 号：TM75[电气工程—电力系统及自动化]