A study on failure diagnosis methods in power cables and their applications

Continuous development of urban areas and extending industrial zones have lately generated an accentuated trend in the transition from aerial electrical lines to cable lines. At the same time with this transition, a number of problems occurred connected to the normal operation of the power cables and their use in powering domestic and industrial electric consumers. This work discusses actual issues on the design of techniques and methods to detect failures of power cables, design based on the data collected by specialized operators. Selecting the correct diagnosis technique can identify quickly, with low errors, the location of the cable defect. This work presents the use of two cable lines diagnosis methods in concrete situations: the impulse method and the returned flame arc method. The current impulse method is characterised by high measure precision and non-destructiveness, being recommended for defect location where long use and aged power cables are involved. The comparison between the two diagnosis methods underlines the detection errors that imply high time and financial costs. The current pulse method is recommended also for power cables mounted within PVC tubes, with no direct contact with earth.