Abstract
Partial discharge is one of the causes of deterioration of insulating polymer materials subjected to high voltages.In this case, the deterioration that is caused by partial discharges in gaps, such as voids inside an insulator is of particular importance.In this study, the prediction of tree initiation due to partial discharge occurring in void is considered. New tree initiation diagnostic methods are proposed by measuring discharge magnitude & discharge luminescence in each phase angie section of the applied voltage.It is noted that some samples revealed different time dependence of partial discharge patterns even under the same measurement condition. These patterns were the case of occurrence of swarming pulsive microdischarge(SPMD)before tree initiation & nooccurrence of SPMD. The prediction of tree initiation by using moving average of the discharge magnitude is discussed. We propose the parameters to reflect apre-tree initiation mode and also evaluate their usefulness for the prediction of tree initiation by using moving average analysis.
