Modeling and simulation of the influence of the metal particle on the characteristics of anode jets in vacuum arc

In the modern power system, vacuum circuit breakers with excellent breaking performance gradually develop their application range to high voltage levels. When the vacuum circuit breaker breaks a high current, the anode surface receives a significant amount of energy flux and rapidly heats up and melts, evaporates to produce metal vapors and even splashes metal particles between the electrodes. When the temperature of the anode surface and the metal particle is high enough, the saturated vapor pressure generated by the evaporated neutral atoms is enough to be equivalent to the arc column pressure, a large number of neutral atoms can’t be completely ionized at this time, which enters into the arc column region to impact the arc column plasma characteristics, and even lead to the failure of breaking. This paper establishes a vacuum arcing model considering the influence of the metal particle on the characteristics of anode jets. Results demonstrate that the density of neutral atom vapor evaporated from the anode surface is much higher than that of the metal particle. Strong ionization occurs at the interface with the interelectrode plasma, generating a large number of ions, and at the same time, a bright ionizationrecombination layer is generated at the edge of the anode jet and around the metal particle; the temperature of the neutral atoms evaporated from the anode surface gradually decreases from the anode, but there exists a small high-temperature region under the metal particle. Since the overall neutral atom vapor has a lower temperature relative to the plasma temperature of the arc column, it has an obvious cooling effect on the arc column.