Speaker
Description
Abstract - Since vacuum interrupter is a native AC current interruption device, new methods should be developed for DC current interruption. The objective of this work is to propose a DC current interruption method by applying a controllable rotating transverse magnetic field on vacuum arc. The experiment was conducted using an L-C-R discharge circuit, with the DC arc current ranged of 80-320 A and the voltage ranged of 120-320V. An external rotating transverse magnetic field was applied on a vacuum interrupter. The rotating magnetic field was generated by two vertically placed Helmholtz coils and the current in the two coils has a phase angle of 90°. The rotating magnetic field strength is controlled by the charging voltage of capacitors in a range of 0-33 mT. The frequency of rotating magnetic field is controlled by the current frequency of the Helmholtz coils, which is set as 230 Hz, 430Hz and 740 Hz, respectively. Experimental results showed that the DC current interruption capacity depended on a magnitude window of the rotating transverse magnetic field. If the applied magnetic field strength was higher than the window, the DC current can always be interrupted successfully. If the applied magnetic field strength was in the window, there was some interruption failures. If the applied magnetic field strength was below the window, the interruption always failed.
