Understanding of Electrical Treeing in PMMA by Partial Discharges and Thermally Stimulated Discharges

Experiments have been conducted to find out whether partial discharges (PD) can characterize tree growth and whether modifying the nature of trapped charges by subjecting the samples aged by PDs to thermally stimulated discharging (TSD) procedure can alter these characteristics. Our earlier experiments have indicated that treeing could be characterized by PDs. The parameters of Weibull distribution are affected by the removal of charges by TSD. The parameters of Weibull distribution are correlated to one another and with time of aging. Several Weibull plots, TSD curves and a number of microphotographs have been studied.