Electrical aging and life models: the role of space charge

• Published in: IEEE transactions on dielectrics and electrical insulation Vol. 12; no. 5; pp. 876 - 890
• Main Authors: Mazzanti, G., Montanari, G.C.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-10-2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aging; Dielectrics and electrical insulation; Life estimation; Life testing; Microscopy; Plastic insulation; Polymers; Space charge; Thermal degradation; Thermal stresses
• ISSN: 1070-9878; 1558-4135
• DOI: 10.1109/TDEI.2005.1522183

This paper has the aim of providing a view of a lively debated topic which has broad impact on the design of electrical apparatus and new insulating materials, that is, the interaction between space charge and aging processes of polymeric insulation. Aging models developed in recent decades that consider explicitly or implicitly the contribution of space charge to insulation degradation, under both DC and AC voltage, are dealt with, with the intention to point out their range of validity. Some conventional phenomenological models that have been used for much more than two decades without referring to space charges can be exploited to account for electrical field and activation energy modification due to space charge. These, together with models conceived considering space charges as the driving force for aging, are especially examined. In addition, recent models that disregard the action of space charge as an ageing factor, but consider space charge as the consequence of degradation processes are also discussed.