Switch Hybridization: Micro-Arcing Model and Color Analysis

Hybrid switches use both mechanical and solid state technologies to perform the switching function. They combine the advantages of both, in particular galvanic isolation, fast opening and closing. Hybridization allows increasing the life of the contacts and extending the operating voltage. Theoretically, hybridization can eliminate the arc generated when opening and closing the switch. However, it seems that there is still a presence of micro-arcing across the contacts. One hypothesis is that micro-arcs could be mistaken for melted bridges. Indeed, melted bridges current and voltage signals are similar to micro-arcing. To see the differences between an arc and a melted bridge, we present a hybridization experiment. We analyze the color of the presumed micro-arcs using a spectral measurement of the light generated. The experimental results show that the micro-arcing and melted bridges may be both present at the opening of the contact.