Optimization of high-voltage self-blast interrupters by gas flow and electric field computations

Self-blast interrupters have the advantage of operating with low mechanical energy as they build up the pressure of the arc extinguishing gas flow from the thermal energy of the arc. This creates a higher pressure, but also a higher gas temperature than in interrupters with mechanical compression. Detailed flow field and electric field computations are necessary to achieve under such conditions the energy removal and dielectric recovery in view of an increase in breaking capacity and voltage rating. In particular, the optimization of the electric field/gas density distribution E//spl rho/ is a tool to improve the short-circuit and capacitive current breaking performance.