The Nonlinearity Factors in Analysis of a Conductive Arc Track

The corrections introduced by an accurate numerical analysis of actual nonlinear thermal conditions in a conductive track under an arc are compared to those for the linear approximation up to the ablation stage. The relevant nonlinearity factors are: the actual arc-current and power distribution, temperature dependences of insulation properties and their stepwise change at the phase transition, and voltage gradient feedback from the track temperature. The plot of temperature distribution in the track shows that the error introduced by the use of a linear approach can be considered as moderate when area of the track which are important for the recovery dielectric strength are considered.