Journal ArticleDOI
The role of trapped space charges in the electrical aging of insulating materials
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TLDR
In this article, the effect of trapped space charges on the aging of polymeric insulating materials subjected to thermo-electrical stress is investigated, and the model which derives from this approach is characterized by electrical and thermal thresholds, its parameters have a physical background, and it can be cast into a probabilistic framework.Abstract:
An investigation of the effect of trapped space charges on the aging of polymeric insulating materials subjected to thermo-electrical stress is reported in this paper. Possible scenarios of degradation mechanisms, thermally activated, but accelerated by the presence of space charges, are examined. The model which derives from this approach has some interesting features: it is characterized by electrical and thermal thresholds, its parameters have a physical background, it can be cast into a probabilistic framework. Acceleration of aging due to space charges is attributed to a reduction of the free-energy barrier to degradation, seen as a local partially-reversible reaction, which is caused by energy stored in space-charge centers. The validity of the model is limited to dc voltage, and to the time of formation of microcavity-crazes, rather than to breakdown times, since other mechanisms will occur under electrical field once large enough cavities are formed in the insulation. The model is applied to the results of thermo-electrical life tests performed on PET, showing very good fitting, as well as interesting relationships between parameter estimates and insulation morphology. It is shown that the model can also fit well to ac life data, where it takes on a phenomenological meaning.read more
Citations
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Journal ArticleDOI
Molecular modeling of electron traps in polymer insulators: Chemical defects and impurities
TL;DR: Meunier et al. as discussed by the authors used density-functional theory to calculate trap energies for a set of chemical impurities and additives commonly found in polyethylene used for high-voltage cable insulation.
Journal ArticleDOI
Properties of Polymer Composites Used in High-Voltage Applications.
TL;DR: The use of polymer micro/nanocomposites in electrical engineering is very promising and further research work must be accomplished in order to diversify the polymer composites matrices and to improve their properties.
Journal ArticleDOI
Advanced polymeric dielectrics for high energy density applications
Tran Doan Huan,Steve Boggs,Gilbert Teyssedre,Christian Laurent,Miko Cakmak,Sanat K. Kumar,Rampi Ramprasad +6 more
TL;DR: In this article, the challenges and opportunities surrounding capacitor materials development/discovery in a practical context are reviewed, and several hierarchical considerations ranging from dielectric, electronic, morphological, processing, reliability and electrical characteristics need to be confronted and addressed adequately before one can progress from biaxially oriented polypropylene toward next generation materials.
Journal ArticleDOI
Short-term breakdown and long-term failure in nanodielectrics: a review
Shengtao Li,Guilai Yin,George Chen,Jianying Li,Suna Bai,Lisheng Zhong,Yunxa Zhang,Qingquan Lei +7 more
TL;DR: In this article, a ratio k has been proposed to compare the electric properties of the nanodielectrics with the matrix and assess the effect for nanoparticles doping on the short-term breakdown and long-term failure properties.
Journal ArticleDOI
Molecular modeling of electron trapping in polymer insulators
M. Meunier,Nick Quirke +1 more
TL;DR: In this article, the role of defects at the molecular level in electron trapping and the formation of space charge in polyethylene has been investigated, and it is shown that both physical (e.g., conformational defects) and chemical defects may be present in insulating materials and may both trap electrons.
References
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Book
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TL;DR: In this paper, the physical and chemical structure of polymers and their breakdown are discussed, along with the stochastic nature of break-down from empirical and modelling viewpoints, and practical implications and strategies for engineers.
Journal ArticleDOI
Theory of Transient Space-Charge-Limited Currents in Solids in the Presence of Trapping
TL;DR: In this article, the problem of transient space-charge-limited currents in insulating and conducting crystals is treated mathematically and solutions are derived for the time-dependent current and space charge distribution following the onset of injection, the latter taking place via an ohmic contact under an applied voltage-pulse.