Experiences from on-site PD measurements using oscillating wave test system

In this paper experiences of partial discharge measurements on medium voltage power cables in the field are discussed. Several examples are used to indicate different aspects of diagnosing service aged power cables. It is shown that the PD activity in power cables usually originates from cable accessories, but sometimes from the cable insulation too. Furthermore, it is shown that measured PD activity may not always originates from a clear location in the cable sections.