Speaker
Description
Vacuum arc interruption is the core issue in vacuum circuit breaker. The interruption process can be generally divided into two parts, arc-burning stage and post-arc dielectric recovery stage. Between these two stages, current zero serves as a connection, in which the arc plasma varies dramatically that the variation in the particle density can exceeds multiple orders of magnitude. The complexity of this physical process causes trouble to the continuous simulation of the whole interruption process. Thus, previous simulation researches chose only one stage for the most part, leading to the plasma evolution during the whole vacuum interruption remaining unclear. To understand the vacuum interruption comprehensively, it is inevitable to fulfil a continuous simulation. In this work, hybrid modelling of vacuum arc is conducted from the arcing stage to the current zero and then to the post-arc stage. During the arcing stage, hybrid plasma model, which treats ions as particles and electrons as fluid, is established, dynamic behaviors of cathode spots also considered. As the circuit current is cut off, the plasma distribution from hybrid plasma model is set as the initial condition of the post-arc stage, and then the plasma dissipation is simulated through hybrid Maxwell-Boltzmann model. Factors, such as plasma density, drift velocity of ions, concentration and asymmetry in plasma distribution, on the plasma dissipation are investigated. This simulation work gives a more accurate description for the physical process in the continuous transition in the vacuum interruption.
