The Morphology and Voltage Characteristics of DC Vacuum Arc during the Rotation and Disconnection Process of Magnetic Control Contacts

In order to explore the arc shape and voltage characteristics of magnetic contact under DC breaking mode of vacuum arc, this paper proposes an additional cathode rotating motion mode on the basis of straight breaking. Since the self-generated magnetic field of the magnetic contact will affect the vacuum arc, finite element simulation software is used to analyze the magnetic field of the magnetic contact under the rotating cathode breaking mode, and a detachable vacuum arc interrupter test platform is built. The morphological evolution and voltage characteristics of vacuum arc between swastika-shaped transverse magnetic contact and cup-shaped longitudinal magnetic contact during direct and rotary breaking are compared and analyzed. The experimental results show that under the rotating breaking mode, the arc burning time of the vacuum arc is shorter due to the joint action of the contact magnetic field and the rotating centrifugal force, and the transformation of the vacuum arc from confined type to diffused state is accelerated. The rotating breaking mode accelerates the arc spot motion on the cathode surface, which makes the arc energy escape faster and improves the arc quenching ability effectively.