Improvement in Cable Defects Assessment using Time Domain Reflectometry Technique

Abstract

Background/Objectives: This study examines the potential of time domain reflectometry (TDR) technique in locating fault accurately along a cable due to cable insulation degradation and degradation at cable joint. Methods/Statistical Analysis: This study involves experimental verification of TDR technique in cable defect localization and identification. The experiment is divided into two parts. Part 1 investigates the ability of TDR to detect cable defect due to cable insulation degradation while part 2 investigates the effect of defect due to degraded cable joint on the TDR results. TDR results are analyzed to identify the reflections due to insulation and jointing degradations. Findings: A degraded cable can be identified by evaluating the velocity of propagation where signal propagates slower in a degraded cable, which causes delay in the reflections. A cable joint can be detected by TDR through a pair of reflections, which consists of a positive peak followed by a negative peak. A degraded joint can be recognized by comparing the amplitudes of the positive and negative peaks reflected where degraded joint gives higher positive and negative peaks. Application/Improvements: Improves the cable defects assessment by indicating the degradation of cable insulation and jointing, and pinpointing the degradation location through the time domain reflectometry technique.