电热联合老化下车载电缆终端复合绝缘结构的太赫兹频域特征  

Terahertz Frequency Domain Characteristics of Composite Insulation Structure for Vehicle Cable Terminals Under Combined Electrical and Thermal Aging

作　　者：李帅兵 李天耕 杨栋[2] 淡嘉豪 康永强 董海鹰 LI Shuaibing;LI Tiangeng;YANG Dong;DAN Jiahao;KANG Yongqiang;DONG Haiying(School of New Energy and Power Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;School of Automation and Electrical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学新能源与动力工程学院,兰州730070 [2]兰州交通大学自动化与电气工程学院,兰州730070

出　　处：《高电压技术》2023年第10期4317-4326,共10页High Voltage Engineering

基　　金：国家自然科学基金(52167018)。

摘　　要：车载电缆终端作为高速铁路动车组供电系统的核心部件,因运行中长期经受电应力、热应力作用极易老化,进而导致绝缘水平下降。为解决现有条件难以有效评估车载电缆终端绝缘状态的问题,设计了不同老化梯度下的电热联合联合老化实验,提出采用太赫兹频域特性表征车载电缆终端复合绝缘结构的老化状态。通过加速老化实验,测试得到了不同老化状况下车载电缆终端复合绝缘结构的太赫兹频域特性参数,包括吸收系数、介电常数实部、介质损耗和折射率。结果显示:太赫兹频域特性参数随老化时间呈现出明显的梯度变化规律,随着老化时间增加,吸收系数呈现先升后降的趋势;介电常数实部、介质损耗和折射率均出现了不同程度的增大。上述结果表明:吸收系数、介电常数实部、介质损耗和折射率等太赫兹频域特征可以用来表征电热联合老化下车载电缆终端复合绝缘结构的老化状态,可作为电缆终端等复合绝缘结构的老化评估的新手段。As a pivotal component in the power supply system of high-speed trains,the cable termination undergoes significant aging and insulation degradation due to prolonged exposure to electrical and thermal stress.To solve the problem that it is difficult to effectively assess the insulation condition of the cable termination under existing conditions,we designed a combined electrical and thermal accelerated aging experiment with different aging gradients,and proposed a terahertz frequency domain characteristic to characterize the aging status of the composite insulation structure of vehicle mounted cable terminals.By conducting accelerated aging experiments,we obtained the terahertz frequency-domain parameters of the composite insulation structure of the cable termination under various aging conditions,including absorption coefficient,real part of dielectric constant,dielectric loss tangent,and refractive index.The analysis reveals distinct gradient variations in the terahertz frequency-domain parameters with aging time.Specifically,the absorption coefficient initially increases and then decreases as aging progresses,while the real part of dielectric constant,dielectric loss tangent,and refractive index all increase to various degrees.The above results indicate that terahertz frequency domain characteristics such as absorption coefficient,dielectric constant,tangent value of dielectric loss,and refractive index can be used to characterize the aging state of composite insulation structures of vehicle cable terminals under combined electric and thermal aging,and it can be used as a new method for evaluating the aging of composite insulation structures such as cable terminals.

关 键 词：车载电缆终端 电热老化 复合绝缘结构 太赫兹 无损检测 

分 类 号：U463.6[机械工程—车辆工程]