Influence of the Ignition Position of the Transverse Magnetic Field Contact on the Forced Characteristics of Vacuum Arc

For high current vacuum arc under transverse magnetic field, the ignition position is significantly related to the forced characteristics and interrupting capacity of the vacuum arc. The objective of this paper is to determine the influence of the ignition position of the transverse magnetic field (TMF) contact on the forced characteristics of the high current vacuum arc. To compare and evaluate the B-field distribution between the different kinds of contacts systems, static 3-D B-field simulations of the TMF contacts were performed. The Lorentz force of arc at the arc current peak was calculated under the assumption that one arc column was at the different position of the arm. The calculation results indicate that, with the arc igniting on the turning point of the contact arm at the distance increasing, the amplitude of the B-field around the arc and the total Lorentz force gradually increases. As the arc ignited from the front of the contact arm to the end of the contact arm, the amplitude of the B-field around the arc and the total Lorentz force gradually increases.