Properties of intermediate-frequency vacuum arc in sinusoidal curved contact and butt contact

In this report, two new contact structures of a vacuum interrupter with a sinusoidal curved surface are proposed to improve the capability by increasing the surface area. The experimental investigation of vacuum arc at intermediate frequency (360-800 Hz) was conducted and the results were compared with a butt contact with the same contact diameter (41 mm) and the same material. By analyzing the arc behavior, arc voltage characteristics, arc energy, current interrupting capacity, ablation of the anode contact and condensation of the arc products at a 3 mm gap, the differences in their vacuum arc characteristics were determined. The correlations of their arc energy with the amplitude and the frequency of the current were also achieved. Analysis suggests that the ruled curved contact has strong application potentiality because of its low arc energy, low arc voltage noise and arc voltage peak, light ablation on the surface of the anode contact and high interrupting capacity.