Current Balance Characteristics of Twin Vacuum Arc Columns of Horseshoe-type Electrode

The objective of this paper is to determine current balance characteristics of twin vacuum arc columns of a horseshoe-type bipolar axial magnetic field (AMF) electrode. Drawn arc experiments were carried out in a demountable vacuum chamber. A split horseshoe-type electrode was fixed to the vacuum chamber. A normal horseshoe-type electrode was set as moving electrode. In the experiment, the split electrode worked as anode and cathode successively. Both anode current and cathode current self-balance processes of two arc columns with damping characteristic were observed. When experiment current was 32.5 kA, the maximum value of anode current difference between left and right columns was 4.2 kA. The maximum arc current unbalance ratio of 15.5%. When experiment current was 19.3 kA, the maximum value of anode current difference between left and right columns was 1.5 kA. The maximum arc current unbalance ratio of 8.9%. Besides, the arc's initial position was a main factor to determine in which arc column current was higher after electrode separation.