基于阻抗评估电缆缓冲层间隙状况的实验与分析

摘要

In order to study correlation between buffer layer gap condition of the high voltage cable and impedance of the buffer layer, the paper respectively builds the buffer layer gap model of high voltage cable and the distributed circuit model of the cable from the outer shield layer end to the aluminum sheath end.On the Simulink platform, it analyzes variation law s and reasons for impedance of the buffer layer under different gap conditions.It designs and establishes an experimental platform for impedance of the buffer layer and makes analysis on six target cables w ith different gap conditions.The results indicate that the impedance curve of the buffer layer of the high-class and closely contacted cable is inw ards concave smooth parabola, and as the port voltage is 10 V, impedance value is less than 150Ω.While the impedance curve of the buffer layer of the poor and loose cable has no fixed law s, and as the port voltage is 10 V, impedance value is greater than 200Ω.The experimental results could provide references for cable quality evaluation and safe operation.%为了研究高压电缆缓冲层的间隙状况与缓冲层阻抗的相关性,分别建立高压电缆缓冲层间隙模型和电缆的外屏蔽层端部至铝护套端部的分布式电路模型.通过Simulink平台分析不同缓冲层间隙状况下的缓冲层阻抗变化规律及原因.设计并搭建高压电缆缓冲层阻抗的实验平台,对6条不同间隙状况的目标电缆进行实验分析.结果表明:优质的、紧密接触的电缆缓冲层阻抗曲线均为向内凹陷的平滑抛物线,在端口电压为10 V时,其缓冲层阻抗值小于150Ω;劣质的、较为松动的电缆缓冲层阻抗曲线无固定规律,在端口电压为10 V时,其缓冲层阻抗值大于200Ω.实验结果可供电缆质量评估与安全投运提供参考.