Patterns of partial discharge activity in XLPE: from inception to breakdown

With the aim of developing defect-based life models (i.e., life models were breakdown is explicitly associated with the partial discharge-induced growth from a defect beyond a critical level), measurements were carried out in the lab on XLPE sandwich test models containing artificial defects. During aging, PD activity was continuously monitored, while the test was stopped shortly at regular times to measure the evolution of PD inception voltage. The results obtained so forth allow to highlight some features of the PD processes prior breakdown. In particular, a quasi-deterministic series of stages can be observed in the trend lines of statistical markers associated with PD magnitude and repetition rate.