A novel technique for on-line PD localisation based on PD signal propagation characteristics in HV power cable

This paper presents a novel PD localisation method, to be referred to as Rise-Time Analysis (RTA) method, for use in on-line cable PD monitoring system. This is based on the change in rise time as a function of cable length along which a PD pulse has propagated. A comparison with four other well-known location techniques, i.e., Time-Domain Reflectometry (TDR), Phase difference, Arrival Time Analysis (ATA) and Amplitude-Frequency (AF) mapping has been made and presented. Analysis shows that the TDR and Phase difference method, although requiring a single measurement point, are only applicable to short length cable systems and where a PD pulse would experience reflection and the reflected pulse would still be observable when it reaches the detection point. On the other hand, the AF and ATA mapping, which can be applied to longer cable systems, need to install detectors at multiple points. In comparison, PD localisation by the proposed RTA method, requires only one measurement point, can be used to localise a PD source which is further away from the PD detection point than other methods and can be used in on-line PD monitoring systems.