Field fluctuations and fractality in electrical breakdown trees.
P L Dammig Quiña1, I M Irurzun, L M Salvatierra
1CCT La Plata-CONICET, Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Repúblic of Argentina.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|January 15, 2011
Summary
This study modifies the discharge avalanche model to investigate space-charge effects on electric tree fractals. The findings reveal nonmonotonic behaviors and voltage-dependent transitions in tree growth and failure times.
Area of Science:
- Materials Science
- Electrical Engineering
- Physics
Background:
- Electric trees are fractal structures formed during dielectric breakdown in polymers.
- Understanding their formation is crucial for predicting material failure.
- Space-charge effects are known to influence electrical discharge phenomena.
Purpose of the Study:
- To explore the role of space-charge characteristics in the fractal nature of electric trees.
- To modify the discharge avalanche model to incorporate local electrical field fluctuations.
- To correlate model predictions with experimental data.
Main Methods:
- Modification of the Dissado discharge avalanche model.
- Inclusion of stochastic fluctuations in the local electrical field (E(loc)) around the Laplacian field (E(lap)).
- Limiting fluctuations to intermediate values of E(lap).
Main Results:
- Prediction of nonmonotonic behavior in average time to failure.
- Prediction of nonmonotonic behavior in the average fractal dimension of electric trees.
- Prediction of a transition from branched to runaway electric trees with increasing applied voltage.
Conclusions:
- Space-charge characteristics significantly influence the fractal geometry and failure dynamics of electric trees.
- The modified model provides insights into the complex behavior of dielectric breakdown.
- The model successfully predicts voltage-dependent transitions in electric tree morphology.
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