Interaction of Dynamic Electric Arc Plasma and Flow Field in Thermal-Puffer SF6 Gas Circuit Breaker

To be compact in size and interrupt high currents with a low driving energy, many high-voltage puffer SF₆ gas circuit breakers (GCBs) introduce and apply the current-interruption principle of a thermal-puffer GCB. Therefore, an analysis program is developed to understand the dynamic arc-plasma quenching process in a thermal-puffer GCB. In the program, the fluid-in-cell method and enthalpy-flow arc model were used for the gas and arc-heat analyses, respectively. A thermal-puffer GCB is used as a test subject to validate the arc-heat analysis, as arc energy flows into the puffer cylinder, resulting in an increase in pressure for the interruption capability by itself without other compression assistance. The pressure increase was measured and compared with the calculated results. Furthermore, differences were observed in the results when the volume of the puffer cylinder was varied. The thermal interruption characteristics can be predicted by investigating the interaction of the dynamic electric arc and gas-flow field in a thermal-puffer GCB with regard to the temperature distribution near the current zero point.