Numerical simulation of a moving high-current vacuum arc driven by a transverse magnetic field(TMF)

The present modeling deals with the physical description of the high-current (>10 kA) constricted vacuum arc, driven by a transverse magnetic field (TMF), as found in vacuum circuit breakers applying TMF arc control. The MHD approach together with detailed heat transfer and evaporation equations for the electrodes are used to describe the arc behavior self-consistently, restricting to two dimensions (2D). A newly developed model describes the cathode attachment of the constricted arc in form of a large laterally extended foot point, instead of the regular cathode spots. This model leads to the characterization of the physical quantities of the arc plasma and describes the arc motion as step-wise due to the different velocities of the current attachment areas of cathode and anode