Steady-state characteristics of a thermally switching cylindrical insulator

Abstract
Normalized steady‐state temperature and current density distributions and V‐I characteristics were determined for thermally switching cylindrical insulators. The results were obtained by solving the equation of conduction of heat by numerical methods, assuming that the electrical conductivity σ obeys the relation σ3=Ae−B/T . Comparison with the analytical solution of the heat conduction equation for the case that σ2=SeaT shows that the two cases differ considerably. In the latter case, on switching, highly concentrated current filaments are formed at relatively small temperature rises. By contrast, in the first case, filaments either do not form, or are much less concentrated, though the temperature rises are relatively large.