摘要
为解决传统频域反射法(FDR)在诊断电缆接头受潮缺陷时易误判的问题,本文提出一种基于热激励下频域反射特性的受潮诊断方法。首先分析了热激励对受潮电缆接头特征阻抗的影响规律,提出了基于热激励下频域反射特性的电缆接头受潮诊断方法,然后在长度为58 m的10 kV XLPE电缆上设置受潮接头,用加热带改变受潮接头的温度,随即对受潮缺陷进行定位诊断。结果表明:施加热激励时,电缆本体、正常接头的单位电容和特征阻抗几乎不随温度变化而改变,受潮电缆接头的单位电容随温度升高而减小,特征阻抗随温度升高而增大;仿真结果表明,不同温度下的频域反射图谱在受潮接头处的幅值随温度升高而升高,在正常接头处的幅值基本不变。基于上述研究结果,通过热激励得到不同温度下真实电缆反射系数谱在接头处的幅值变化实现了受潮缺陷的定位诊断。
To resolve the issue that the traditional frequency domain reflection(FDR)method is easy to misjudge when diagnosing the moisture defects of cable joints,the influence law of thermal excitation on the characteristic impedance of moistened cable joints was firstly analyzed in this paper,and a diagnostic method for moisture in cable joints was proposed based on the frequency domain reflection characteristics under thermal excitation.Then a moistened joint was set up on a 10 kV XLPE cable with a length of 58 m,the temperature of the moistened joint was changed using a heating belt,and the moisture defects were located and diagnosed.The results show that when applying the thermal excitation,the unit capacitance and characteristic impedance of the cable body and normal joint hardly change with the temperature,the unit capacitance of the moistened cable joint decreases with the increase of temperature,and the characteristic impedance increases with the increase of temperature.The simulation results show that the amplitude of the frequency domain reflection spectrum at the moistened joint increases with the increase of temperature,while the amplitude of the frequency domain reflection spectrum at the normal joint is basically unchanged.Based on the above research results,the amplitude changes of the true cable reflection coefficient spectrum at the joint under different temperatures were obtained through thermal excitation,achieving the localization diagnosis of moisture defects.
作者
徐忠林
冯阳
丁玉琴
饶显杰
周凯
杨帆
刘凤莲
XU Zhongin;FENG Yang;DING Yuqin;RAO Xianjie;ZHOU Kai;YANG Fan;LIU Fengian(Chengdu Power Supply Company,State Grid Sichuan Electric Power Company,Chengdu 610041,China;School of Electrical Engineering,Sichuan University,Chengdu 610065,China;State Grid Sichuan Electric Power Research Institute,Chengdu 610072,China)
出处
《绝缘材料》
北大核心
2025年第2期121-128,共8页
Insulating Materials
基金
国网四川省电力公司科技项目(521904230003)。
关键词
热激励
电缆接头
受潮缺陷
定位诊断
thermal excitation
cable joints
moisture defects
positioning diagnosis
