Effects of geometry of auto-expansion volume on SF6 ARC behaviour

Summary form only given. High pressure plasmas play important roles in modern high-voltage auto-expansion circuit breakers that are normally filled with Sulphur Hexaflouride (SF₆) since it is an excellence medium for extinguish the arc and has excellent insulation properties to withstand the induced voltage transients after arc extinction. An auto-expansion circuit breaker utilizes the energy dissipated by the arc itself to create the required pressure in the expansion volume for arc quenching at current zero. Therefore the geometry of the expansion volume plays an important role in the circuit design as it affects the flow and thermodynamic properties of the gas in the volume that in turn Σhave decisive effects on the performance of the circuit breaker.