PD Detection Limits in Extruded Power Cables Through Wide and Ultra-Wide Bandwidth Detectors

The aim of this paper is to infer partial discharge (PD) detection limits in extruded cables as a function of the distance between PD source and detection point. The investigation is carried out for different types of detectors, from IEC 60270-compliant to ultra-wide bandwidth systems. For this purpose, a medium voltage cable has been modelled as a transmission line with frequency-dependent parameters accounting for skin effect, dielectric and semicon characteristics. Pulse propagation through the cable has been predicted for very long distances. Different filters have been used to simulate different detectors, emphasizing the behaviour of these systems, particularly the features of sensitivity, noise rejection, PD source separation and PD source localization.