Numerical Simulation and Experimental Investigation of the Influence of Gap Distance on Vacuum Arc Characteristics Between TMF Contacts

The arc between the vacuum transverse magnetic field (TMF) contacts is driven by the TMF generated by contacts to move at high speed. The motion characteristics of the arc determine the key parameters, such as contact surface temperature and metal vapor density during the arcing process, which are closely related to the breaking capacity of the vacuum switch. Under the conditions of different gap distances, the motion characteristics of the vacuum arc during the arcing process are significantly different. In this article, a magnetohydrodynamic (MHD) simulation model is established by the method of modeling and simulation, and the variation characteristics of plasma parameters during the movement of the vacuum arc under different gap distances are studied. The results show that with the gap distance increasing, the maximum electron temperature in the center of the arc column increases and the position gradually approaches the anode, and the average moving speed of the arc first increases and then decreases. At the same time, experiments are carried out on the vacuum contacts in the checkable vacuum interrupter to analyze the influence of the gap distance on the arc motion and arc shape changes, and the simulation results are verified. The research in this article shows the influence of the variation of the gap distance on the arc motion characteristics, which provides a theoretical basis for designing contacts with better breaking capacity.