Monte Carlo Simulation Of Laminar Composite Breakdown In DC Field

Open Access
Author:
Koch, Benjamin T
Graduate Program:
Engineering Science
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 08, 2011
Committee Members:
  • Michael T Lanagan, Thesis Advisor
  • Eugene Furman, Thesis Advisor
Keywords:
  • Capacitor
  • Energy Storage
  • Monte Carlo
  • Breakdown
  • Composite Dielectric
  • Dielectric
  • composite
  • simulation
  • dielectric contrast
  • dielectric barrier
  • barrier
Abstract:
The objective of this project is to utilize computer model to simulate and explore the effects of a high-permittivity (k) barrier located between capacitor plates on dielectric breakdown properties. By improving our knowledge of electric breakdown and degradation in composite dielectrics it is hoped that a more reliable capacitor with a graceful failure mechanism can be developed. Using Mathsoft’s MathCad 13 software, a Monte Carlo based computer simulation was developed to model the treeing phenomena found in capacitor breakdown. The model explored the electrostatic effects of adding a high-k barrier within an existing dielectric causing a dielectric contrast and distorting the electric field. In the program, normalized local fields are compared to a random number between 1 and 0 to determine breakdown events. Weibull statistics were applied to the collected data and characteristic number of breakdown steps was compared between runs. Run conditions explored dielectric contrasts of 2, 10, 50, 100 and a homogeneous matrix. Barrier location was varied from ¼ to ¾ of the distance between capacitor plates and occupied 2 of 60 vertical spaces (3.3%) of capacitor thickness. Characteristic breakdown steps for each condition did not show significant trends until higher contrast values. It was noted that average time spent within the barrier increased with barrier distance from the initiation point and the contrast between the barrier and the matrix. It was also observed that lateral growth occurred with higher dielectric contrast values. Further development of the model to incorporate more material properties affecting breakdown would be highly beneficial in understanding current experimental observations.