Recent progress in understanding water treeing phenomena

Several areas where recent progress has occurred in understanding water treeing are reviewed; propagation rate evaluations, distinguishing between initiation and propagation, the influence of antioxidant and voltage stabilizers, and evaluating clustered water. The necessity for distinguishing between initiation (which encompasses the induction period) and prop gation events is emphasized. Some commonalities in pre-partial discharge events for both electrical and water treeing are suggested, along with a definition of tree initiation. Potential roles of antioxidant and water on tree initiation are reviewed. The possibility of antioxidant clusters serving as pro-oxidants rather than anti-oxidants are also discussed.