Indexes for the recognition of insulation system defects derived from partial discharge measurements

This paper presents results of tests having the purpose to derive indexes, from PD measurements, which can enable the recognition of PD generated from different sources, such as internal voids, surface and corona discharges. Moreover, recognition of the location and shape of cavities can be achieved. PD measurements are performed by a digital instrument which allows PD-pulse amplitude, phase and shape to be recorded. Such results can be employed to improve recognition efficiency of PD-based diagnostic tools used for on field applications.