Analysis of the influence of contact rotational motion on the characteristics of vacuum arc plasma

The characteristics of vacuum arc plasma determine the energy dissipation process of the arc during the breaking of vacuum switches. To explore the influence mechanism of the contact rotation motion on the energy transformation of vacuum arcs, a multi-scale coupled vacuum arc model integrating microscopic and macroscopic aspects is established. Based on the thermal-field emission characteristics of the contacts, the physical parameters, such as the density and dynamic viscosity of the high-energy particle flow in the vacuum arc, are analyzed by combining the microscopic particle reactions in the vacuum gap. Based on the physical parameters of the microscopic particles, a three-dimensional magnetohydrodynamic (MHD) model (the MHD equation separates the electron temperature from the ion/heavy particle temperature for solution. Due to the significant differences in the thermal motion speeds and collision frequencies between electrons and heavy particles, insufficient energy exchange results in a significant temperature difference) with rotational characteristics are established to study the effect of contact rotation motion on the more uniform spatial distribution of high-energy particles in the gap. This paper conducts vacuum breaking experiments with contact rotation motion at different arc initiation points. The results show that the contact rotation drives the vacuum arc to move in the gap. The farther the arc initiation point is from the center, the easier the arc enters the diffusion state and the faster the arc energy dissipates, further verifying the validity of the simulation model. This provides a research basis for exploring new technologies to develop high-breaking capacity vacuum switches.