Study on Thermal Stability of Molten Bridge in an Arc-less Hybrid DC Switch

摘要

Arc-less hybrid DC switches have high reliability due to the absence of arc erosion. However, it has been found that the molten bridge generated in arc-less hybrid DC switch is thermally unstable, and easily transfers into an arc. In this paper, the relationship between the contact resistance and thermal stability of a molten bridge is investigated. Experiments are then carried out to explore the influence of the heat dissipation area of contacts on the thermal stability of the molten bridge. The results show that a low contact resistance and a large heat dissipation area can improve the thermal stability of the molten bridge in the arc-less hybrid DC switches.