Study on Localisation of Water Degraded Regions Along Power Cable Insulation Using Time Domain Reflectometry R. Papazyan |
his thesis centres on the initial evaluation of using Time Domain Reflectometry (TDR) as a method for spatial localisation of water degraded regions along medium voltage (MV) cable insulation. Both mass impregnated paper, as well as cross-linked polyethylene (XLPE) insulated three-core cables were investigated. The method used is "Differential TDR Measurements". It includes performing TDR measurements before and after local impedance changes due to water degradation of the cable insulation. Acquired data in both cases is later compared. The resulting curve gives an indication of the water ingress position. This work presents and analyses the acquired and calculated data. Experimental set-up improvements in regards to three-phase pulse propagation and impedance matching are discussed. Also included are measurement precautions and procedures, as well as data acquisition and processing LabVIEWTM software developed for the needs of this study. |