Numerical Study of Delayed-Zero-Current Interruption Phenomena Using Transient Analysis Model for an ARC IN SF6 Flow

Arcs in gas circuit breakers have been regarded as resistances when a zero-miss current interruption phenomenon has been simulated by a computer. However, the model involved is unable to simulate the thermal inertia effect of the arc. This fact is proved to result in a deteriorated simulation accuracy in the vicinity of the current zero point through conducting a short-circuit test. To simulate thermal inertia of the arc, an arc model based on the conservation laws of mass, momentum, and energy is developed. By applying this model to circuit analysis, zero-miss current interruption phenomena are shown to be simulated more precisely up to the current zero point than the conventional method.