Model for electrical tree initiation in epoxy resin

Abstract

A model for electrical tree initiation in epoxy resins is presented in which the process is driven by the generation of new charge traps as a result of energy transferred to the polymer via charge recombination processes. The electroluminescence intensity expected from the model is computed and shown to be in agreement with the experimental data. In particular it is shown how the initial emission due to recombination can change to an emission arising from impact excitation in a natural way when the trap density reaches a level sufficient for the high electric field of the tree initiation region to connect shallow traps to form conducting filamentary paths in the form of percolation clusters. This result allows the electroluminescence behavior to be correlated with the observed onset of filamentary damage. The model is also shown to be able to explain the decrease in emission intensity observed at the time of transition between the two mechanisms for luminescence. England twice he settled in at ChelseaCollege in 1977 to carry out research into dielectrics. His interest in breakdown and associated topics started with a consultancy with STL in 1981. Since then he has published many papers and one book, together with John Fothergill, in this area. In 1995 he moved to The University of Leicester, and was promoted to Professor in 1998. He has been a Visiting Professor at The University Pierre and Marie Curie in Paris, Paul Sabatier University in Toulouse, and Nagoya University, and has given numerous invited lectures, the most recent of which was the Whitehead lecture at IEEE CEIDP 2002 in Cancun, Mexico. Currently he is an Associate Editor of IEEE Transactions DEI, co-chair of the Multifactor Aging Committee of DEIS and a member of DEIS Administrative Committee.

Secondary Ionization Coefficient of MgO and Accumulated Charge

“…At present, the reason for the difference in the dependence of on the accumulated charge, even when the same MgO film electrode is used, is not yet fully understood. However, we note with interest Massine et al's proposal 26) of the existence of shallow traps 27) in dielectrics, which might affect the accumulated charge on the MgO film electrode.…”

Very large-scale gap distances of atmospheric pressure dielectric barrier glow discharge using semiconductor materials

“…The electrons, which are trapped in the shallow traps of the dielectric surface from the gas gap during the previous discharge, are easier to remove than the intrinsic ones. The deepness of the shallow traps is typically 1-2 eV from the void level [27] while the valence band is at 6-8 eV [28]. The cooled dielectric helps the trapped electrons to avoid escape prematurely [29], i.e., the heated dielectric helps to rapidly produce the secondary electrons.…”