Hirayama Satoshi

The authors conduct three-dimensional and time dependent magnetohydrodynamic numerical simulations of a gas circuit breaker model with externally applied magnetic field for CO2 or SF6 gas. The objective of this work is to examine the current interruption process of the gas circuit breaker model with the applied magnetic field for both gases. Numerical results show that applying the magnetic field induces swirl flow, which leads to the pressure rise in the puffer chamber for both gases. Just before second current zero, the arc forms cylindrical shape under the magnetic field for CO2 gas unlike SF6 gas where the arc column forms spiral shape. Arc conductance around the time is reduced by applying the magnetic field for both gases because heat convection around the arc is enhanced. This means that the thermal interruption capability can be improved by applying the magnetic field for both gases.