A model of the electrical breakdown process due to electrical treeing growth

The authors develop a mathematical model that can describe the electrical breakdown due to electrical treeing growth in point-plane electrode specimens of thermoplastic polymers subjected to AC voltage ramps. The damage due to the tree growth is modeled as a conductive sphere, allowing an easy computation of the geometrical field in front of it. The breakdown voltage V/sub BD/, the radius of the sphere R/sub b/, and the electric field on the sphere AE/sub b/ are related by means of the simple equation V/sub BD/(D)=AE/sub b/*R/sub b/(D), where D is the interelectrode gap. The model has been verified experimentally.<
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