Thermal inertia of direct current arcs at different contact material

Inhalt:
In recent years direct current systems have been gaining in importance. Associated therewith direct current electric arcs have been increasingly taken into consideration of research. Thereby one major objective is to improve the modeling of the static and dynamic arc characteristics to simulate its terminal behavior within an electric circuit. These so called black box models require estimated values of the two basic input parameters, “time constant” and cooling power, for every specific arc arrangement. Under simplifying assumptions this so called “time constant” represents the thermal inertia of the arc column. In this paper experimentally determined values of “time constants” are presented dependent on different contact material for a maximum arc length of 10 millimeters. The used experimental circuit was fed by a 230 volts battery system and the maximum current was limited to 12 amperes.