绝缘层厚度对高压直流电缆电场和温度场分布的影响  

Influence of Insulation Layer Thickness on Electric Field and Temperature Field of HVDC Cable

作　　者：魏艳慧 郑元浩 龙海泳 李国倡 李盛涛[3] Wei Yanhui;Zheng Yuanhao;Long Haiyong;Li Guochang;Li Shengtao(Institute of Advanced Electrical Materials Qingdao University of Science and Technology, Qingdao 266042 China;TEBA Shandong Luneng Taishan Cable Co.Ltd, Xintai 271200 China;State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University ,Xi’an 710049 China)

机构地区：[1]青岛科技大学先进电工材料研究院,青岛266042 [2]特变电工山东鲁能泰山电缆有限公司,新泰271200 [3]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《电工技术学报》2022年第15期3932-3940,共9页Transactions of China Electrotechnical Society

基　　金：山东省重大科技创新工程资助项目(2019JZZY010421)。

摘　　要：高压电缆电场和温度场分布是绝缘层厚度设计需要重点考虑的因素。该文建立了高压直流电缆电-热耦合仿真模型;测量并分析电缆绝缘层和半导电屏蔽层的电阻特性和导热特性随温度的变化规律;计算绝缘层厚度对电缆电场和温度场的影响规律,讨论了载流量和敷设方式对不同绝缘层厚度电缆温度场分布的影响。实验结果表明,随着温度的升高(25~90℃),XLPE电阻率下降2~3个数量级,半导电屏蔽层则由21.4Ω·cm增加至75.5Ω·cm;整体上,半导电屏蔽层导热系数约为绝缘层的两倍。将实验参数代入仿真模型,发现绝缘层厚度从20mm增加至35mm时,绝缘层内侧电场降低约34%,绝缘层内外温差增加约54%;随着载流量的增加,绝缘层温差由800A的3.5℃增加到2400A的31.4℃;三种敷设方式散热效率由高至低依次为隧道敷设、直埋敷设和管道敷设。The distribution of electric and temperature fields in high voltage cables is a key factors in the design of insulation thicknesses. In the study, an electric-thermal coupling simulation model of high-voltage direct current(HVDC) cable was established, and the changes of resistivity and thermal conductivity of cable insulation layer and semi-conducting layer with temperature were measured and analyzed. The influence of insulation layer thickness on the distribution of cable electric and temperature fields was calculated. The influence of load capacity and laying method on the temperature field distribution of cable with different insulation layer thickness was discussed. Experimental results show that the XLPE resistivity decreases by 2-3 orders of magnitude with increasing temperature(25-90℃),while the semi-conductive shield increases from 21.4Ω·cm to 75.5Ω·cm. Overall, the thermal conductivity of semi-conducting layer is about twice that of insulation layer. When the insulation thickness is increased from 20 mm to 35 mm, the electric field inside the insulating layer is reduced by about 34%. The temperature difference between inside and outside the insulation layer increases by about 54%. The temperature difference of the insulation layer increases from 3.5℃ for 800A to 31.4℃ for 2400A with the increase of the amperage. The heat dissipation efficiency of the three laying methods in descending order is tunnel laying, directly buried laying and pipeline laying.

关 键 词：高压直流电缆 绝缘厚度 电场 温度场 载流量 电缆敷设方式 

分 类 号：TM853[电气工程—高电压与绝缘技术]