High-current arcs simulation in a puffer-assited self-blast interrupter considered the mechanical stress

In SF₆ puffer-assisted self-blast interrupters, which are being developed as the next-generation switching mechanism, the arc burns within insulating nozzles with an ablation of the nozzle material and leads to an incoming gas flow for the pressure chamber with a pressure-rise during the high-current phase. Close to current zero, the arc can be cooled down and quenched completely by the reverse gas flow from the chamber to the arcing zone according to the pressure gradient between them. Therefore, the interruption of fault currents is dependent on the thermal decay of arcs during the current-zero phase by the blowing-off force, which is generated by the pressure-rise of the chamber during the high-current phase. In this study, we calculated SF₆ switching arcs caused by fault current interruption inside a SF₆ puffer-assisted self-blast interrupter with the reversed stroke of electrode and investigated the thermal breakdown with thermal decay near current zero.