基于频域反射信号衰减强度评估的电缆缺陷长度和类型判别方法

A method for discriminating defect length and type of cable based on attenuation intensity evaluation of frequency domain reflected signal

为解决频域反射法(FDR)只能判别缺陷极性而不能识别缺陷长度和类型的问题,本文提出了一种基于信号衰减强度评估的缺陷类型判别方法,通过利用各缺陷处总的折反射强度与首次反射强度作差,再利用差值的大小即可对缺陷的长度和类型做出判断,并结合极性判断方法将缺陷细分为了4种类型。结果表明:本文所提方法可成功识别电缆中常见的接地故障、过度弯折、本体受潮及长电缆中间接头4种缺陷的长度和类型,且与仿真建模的结果一致。本文缺陷类型判别方法可对电缆常见的点缺陷和段缺陷进行识别。

To solve the problem that frequency domain reflectometry(FDR)can only distinguish defect polarity and cannot identify the defect length and type,a defect type discrimination method was proposed on the basis of signal attenuation intensity evaluation in this paper.The difference between the total refracted reflection intensity at each defect and the initial reflection intensity was calculated,and then the defect length and type can be discriminated by comparing the magnitude of difference.Combined with the polarity judgment method,the defect can be subdivided into four types.The results show that the method proposed in this paper can successfully identify the length and type of four common defects in cables,including grounding faults,excessive bending,cable body moisture,and long intermediate joints of cables,and the recognition results are consistent with the simulation modeling results.The defect type discrimination method in this paper can identify the common point defects and segment defects in cables.