Articles | Volume 12
Adv. Radio Sci., 12, 29–34, 2014
https://doi.org/10.5194/ars-12-29-2014
Adv. Radio Sci., 12, 29–34, 2014
https://doi.org/10.5194/ars-12-29-2014

  10 Nov 2014

10 Nov 2014

Modeling of electrical transport in Zinc Oxide varistors

K. Bavelis, E. Gjonaj, and T. Weiland K. Bavelis et al.
  • Institut für Theorie Elektromagnetischer Felder, Technische Universität Darmstadt, Schloßgartenstr. 8, 64289 Darmstadt, Germany

Abstract. The electrical transport in zinc oxide (ZnO) varistors is analyzed using microstructural material modeling. The fully three dimensional current distribution is computed by means of a nonlinear equivalent circuit model representing the assembly of current carrying grains and grain boundaries of the material. The investigation focuses on the phenomenon of current filamentation due to inhomogeneities of the varistor microstructure. Numerical results highlight the importance of 3-D percolation effects in the modeling of varistor currents as well as that of the grain bulk resistivity which so far has been neglected in previous studies.

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