车载电缆终端应控管热老化特性及对绝缘性能的影响  

Thermal Aging Characteristics of Vehicle-Mounted Cable Terminal Stress Control Tube and Its Influence on Insulation Performance

作　　者：孙传铭 刘凯[1] 张鹏鹏 辛东立 高波[1] 李广建 吴广宁[1] SUN Chuanming;LIU Kai;ZHANG Pengpeng;XIN Dongli;GAO Bo;LI Guangjian;WU Guangning(School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China;Technical Development Department of CRRC Qingdao Sifang Locomotive&Rolling Stock Co.,Ltd.,Qingdao 266111,China;State Grid Nanchong Power Supply Company,Nanchong 637000,China)

机构地区：[1]西南交通大学电气工程学院,四川成都610031 [2]中车青岛四方机车车辆有限公司技术中心电气开发部,山东青岛266111 [3]国网南充供电公司,四川南充637000

出　　处：《西南交通大学学报》2024年第6期1275-1284,共10页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金项目(52007158)。

摘　　要：为研究车载电缆终端应控管热老化条件下的特性及热老化作用下的电缆终端绝缘性能,首先,通过试验研究确定车载电缆终端应控管宏观介电特性及微观老化规律;其次,基于对热老化下应控管材料电导、极化和损耗特性测试进行分析,得到不同老化周期下的介电特性曲线;最后,建立考虑应控管老化特性的车载电缆终端电场有限元模型,并基于热老化下介电参数计算应控管电缆终端电场分布.研究表明:140℃老化条件下电导率上升趋势最为显著,50 kV/m场强下电导率达到最大值1.1×10^(−10)S/m,高温(140℃)老化20 d时,相对介电常数达到最小值14.00,此外,热解反应过程中聚合物长链折叠、断裂等陷阱阻碍作用增强,介质损耗有所增大;在应控管官能团特性及微观形貌上,热老化导致应控管材料烯烃类聚合物发生热解聚反应,形成化学立体缺陷,且加剧应控管试样表面聚合物球晶的裂解以及无机氧化产物的生成,试样表面理化特性发生变化.仿真发现,在热老化条件下电缆终端内部电场畸变区域呈现扩大的趋势,电场畸变区域沿应控管向终端高压方向不断爬伸,最终稳定在乙丙橡胶主绝缘层与应控管的交界处.In order to determine the thermal aging characteristics of the vehicle-mounted cable terminal stress control tube and its influence on the insulation performance of cable terminal under thermal aging conditions,firstly,the macro-dielectric characteristics and micro-aging law of vehicle-mounted cable terminal stress control tube were determined through experimental research.Secondly,based on the analysis of the electrical conductivity,polarization,and loss characteristics of the stress tube material under thermal aging,the dielectric characteristic curves under different aging periods were obtained.Finally,a finite element model of the electric field of the vehicle-mounted cable terminal was established by considering the aging characteristics of the stress control tube,and the electric field distribution of the cable terminal of the stress control tube was calculated based on the dielectric parameters under thermal aging.The results show that the electrical conductivity increases most significantly at 140℃and reaches the maximum value of 1.1×10^(−10) S/m at a field intensity of 50 kV/m.The relative dielectric constant reaches the minimum value of 14.00 at high temperature(140℃)for 20 days.In addition,trap hindrances such as folding and breaking of polymer long chain are enhanced during pyrolysis reaction,and the dielectric loss increases.In terms of functional group characteristics and microstructure of the stress control tube,thermal aging results in pyrolytic polymerization of olefin polymers in stress control tube materials,forming chemical stereoscopic defects.In addition,the cracking of polymer spherulites and the formation of inorganic oxidation products on the surface of the stress control tube sample are intensified,and the physical and chemical properties of the sample surface are changed.Simulation results show that under thermal aging conditions,the electric field distortion area inside the cable terminal presents a trend of expanding,creeps along the stress control tube towards the terminal hig

关 键 词：车载电缆终端 应控管 热老化特性 分子官能团 绝缘性能 电场分布 

分 类 号：TM854[电气工程—高电压与绝缘技术]