Investigation on the arc root characteristics of vacuum arc between the iron-core cup-shaped transverse magnetic field contacts

Abstract

The severity of the contact surface ablation determines the breaking capacity of the vacuum circuit breaker, and the interaction between the arc root and the electrode is the main cause of the contact surface ablation. The characteristics of the arc root determine the magnitude of the electromagnetic force received by the arc during the movement stage as well as the shape and speed of the arc movement. It will eventually affect the temperature of the contact surface and the ablation situation. This paper studied the arc root characteristics of high-current constricted vacuum arcs between the iron-core cup-shaped transverse magnetic field contacts and put forward the idea of using the ratio of cathode and anode arc root areas to quantitatively analyze the concentration of vacuum arc. The research on the arc root characteristics of the vacuum arc can help to improve the arc characteristics and arcing mechanism, and the proposition of the ratio can provide a new method for the study of constricted arc. This can provide a basis for improving the arc extinction performance of the switch, reducing the ablation of the contact material, and improving the contact life.