Modeling and Simulation of Vacuum Arc Considering the Influence of Anode Melting Pool Protrusions

When the vacuum circuit breaker interrupts the high current, the anode surface experiences a significant influx of energy, leading to rapid heating and subsequent melting. Simultaneously, a substantial quantity of metal vapor is generated through evaporation, entering the arc column to interact with the cathode plasma. This paper establishes a vacuum arc burning model that considers the impact of anode melting pool protrusions on the characteristics of the vacuum arc. The results demonstrate that as the number of protrusions increases, the density of neutral atomic vapor also rises. This is due to the larger tip area of big protrusions, resulting in more widely distributed jets. Additionally, larger protrusions worsen the uneven distribution of ions, causing accumulation near the electrode’s edge. When the protrusions are symmetrically distributed around the melting pool, the ion pressure distribution is also symmetrically distributed, and the pressure peak increases with the increase in the number and size of protrusions. When the protrusions are symmetrically distributed on both sides of the anode melting pool, the distribution of their axial ion velocity is also symmetrical. The shape and geometric features of large protrusions may lead to exacerbating asymmetries during ion transport.