Power distribution cable networks are inherently inaccessible and complex systems; many of them are coming to the end of their expected lifespan and are being loaded beyond their original design specifications. The ability to accurately monitor and record the real-time health of these systems is of vital importance to utility companies for activities such as planning, asset management, and pin-pointing possible weaknesses of the network. Partial Discharge (PD) activity has been highlighted as both a cause and symptom of electrical degradation of high voltage equipment. Utilities increasingly use the analysis of PD signals to make more robust maintenance and asset replacement decisions. Additionally, it reduces the likelihood of future supply interruption, and allows replacement or repairs to be planned in advanced. Finally, the use of on-line PD sensing systems can reduce costly down time and help to avoid catastrophic failures.
An EDF Energy Networks sponsored project is taking place at the Tony Davies High Voltage Laboratory, University of Southampton. It involves the introduction of known faults into medium voltage three-phase PILC cable and aims to closely replicate operational conditions. The results produced by the experimental rig in the lab will be obtained using conventional techniques covered by IEC 60270, in parallel with commercially available PD monitoring equipment that is installed in distribution networks worldwide. It is hoped that the research being undertaken will develop the understanding of fault progression with respect to 11 kV three-phase PILC cables.