Arc Jets Characterized by High-speed Shadow Imaging Technique

The arc jet is a common phenomenon during arc movement, which can aggravate the electrode contacts’ ablation, bringing great harm to industrial applications, such as circuit breakers and transmission lines. A high-speed camera system is usually used to record arc jets, which is feasible when the current is relatively large. However, in the case of a small current, few metal particles are ejected from the electrode, and the particle flow is challenging to be observed. Thus, based on the shadow imaging technique, a more effective method is proposed to study arc jets characteristics of small currents. The results show that under the condition of a small- current arc, the main jet direction is always from the cathode to the anode, and the cathode jet is more intense; with the increase of the current, the jet intensity increases; the greater the contact breaking speed, the fewer the total number of jets and the shorter the total duration of jets; using Al instead of Cu and using Al as the anode can increase the jet intensity.