Inception and Propagation of Electrical Trees in the Presence of Space Charge in HVAC Extruded Cables

Background: Electrical trees can affect the distribution of electric field and space charge in cross-linked polyethylene (XLPE) cables, and play an important role in insulation aging and breakdown of cables. Therefore, it is important to study the influence of electrical trees in cables. Methods: In this study, the finite element method of second-order tetrahedral element and electromagnetic theory method are used for calculation. A model of XLPE cable with three-dimensional electrical trees is taken as an example for calculation. Results: The results shows that the longer the trunk length is, the greater the electric field intensity at the end of the branch is; the farther the electrical trees are from the insulation side of the high voltage, the more the electric field intensity of each location decreases. Conclusion: With the increase of the resistivity of the trees, the electric field intensity and charge density tend to be stable at the end of the tree.

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Discharges, space charge, and the shape of electrical trees

ICSD 98 Proceedings of the 1998 IEEE 6th International Conference on Conduction and Breakdown in Solid Dielectrics (Cat No 98CH36132) ICSD-98 ◽

10.1109/icsd.1998.709284 ◽

2002 ◽

Cited By ~ 5

Author(s):

K.S. Bromley ◽

L.A. Dissado ◽

J.C. Fothergill

Keyword(s):

Space Charge ◽

Electrical Trees

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Electron holography of interfaces in electroceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151271 ◽

1993 ◽

Vol 51 ◽

pp. 1088-1089

Author(s):

Vinayak P. Dravid ◽

V. Ravikumar ◽

Richard Plass

Keyword(s):

Space Charge ◽

Direct Evidence ◽

Materials Science ◽

Theoretical Work ◽

Electron Holography ◽

Resolution Limit ◽

Interference Phenomenon ◽

X Ray ◽

Electron Sources ◽

Science Community

With the advent of coherent electron sources with cold field emission guns (cFEGs), it has become possible to utilize the coherent interference phenomenon and perform “practical” electron holography. Historically, holography was envisioned to extent the resolution limit by compensating coherent aberrations. Indeed such work has been done with reasonable success in a few laboratories around the world. However, it is the ability of electron holography to map electrical and magnetic fields which has caught considerable attention of materials science community.There has been considerable theoretical work on formation of space charge on surfaces and internal interfaces. In particular, formation and nature of space charge have important implications for the performance of numerous electroceramics which derive their useful properties from electrically active grain boundaries. Bonnell and coworkers, in their elegant STM experiments provided the direct evidence for GB space charge and its sign, while Chiang et al. used the indirect but powerful technique of x-ray microchemical profiling across GBs to infer the nature of space charge.

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