Analysis of cable failure modes and cable joint failure detection via sheath circulating current

Abstract

Power cables are preferred in urban areas for power transmission and distribution because of their high reliability, environmental friendliness and the visual invisibility. Whilst the volume of underground power cable has been growing steadily, the voltage level of the power cables have also increased significantly in recent years. The increasing volume of high voltage power cables brings about technical challenges to the power system operators and maintenance engineers. One of these challenges is the application of appropriate condition monitoring techniques to detect incipient cable faults and to reduce unplanned outages. This paper aims to analyse the causes, modes and mechanisms, among cable joint failures, and to propose an applicable sheath circulating current monitoring technique with the associated criteria for fault diagnosis. Two joint faults, flooded link box and joint insulation breakdown, are analysed in detail. Finally, a set of criteria is proposed for cable joint fault diagnosis based on the simulation of an 110kV underground power cable system of length 1.5km

Probabilistic dynamic programming algorithm: a solution for optimal maintenance policy for power cables

“…A random failure can occur due to degradation in a small section of a cable circuit such as poor workmanship, a manufacturing defect, or sudden mechanical (Sachan et al 2015b), whereas ageing failures occur in cable insulation due to dominant electrothermal stress in daily load cycle (Sachan et al 2015a, b). Most common mode of insulation failure is electrical breakdown of insulation, breakdown at the electrical interface, and insulation thermal breakdown (Dong et al 2014;Orton 2013). The insulation is the weakest link of a power cable in terms of degradation or failure.…”

“…conduct quality tests on each cable section to detect the expected fault. Transportation of cable to site and installation activities can cause damage to the cable (Dong et al 2014). Transition probability of new cable to next stage can be estimated by infant mortality rate of those cables.…”

Analysis of Cable Screen Currents for Diagnostics Purposes

“…Analysis of cable screen currents gives a possibility to distinguish the type of line (cable or overhead) affected by an earth fault [20]. Furthermore, cable screen current measurements can be used for the detection of problems in cross bonded lines, e.g., short-circuited cable screens during flooding or insulation breakdown in cable joints [21][22][23]. Furthermore, the wrong order of cable screen connections in parallel connected cables can be detected.…”

Simulation Research on On-line Multi-parameter Monitoring for Long Distance Three-phase Power Cable

“…Therefore, it is very importance to ensure the safe operation of power system. Some researchers have built up the metal sheath cross-linked of three-phase power cable [6][7][8]. Boji Sheng and et al [8], proposed an on-line PD detection and localization by installing current sensors at cable joints or terminations.…”