Influence of the different power frequency on interruption simulation for a self-blast type 252kV SF6 circuit breaker

In this paper, an interruption simulation model for 252kV Self-blast SF6 circuit breaker is built according to the MHD theory, using real gas model and dynamic mesh method. Aiming at acquiring the characteristics and the differences of interruption under different power frequency, the gas flow field at different power frequency 50Hz and 60Hz are simulated and compared. Seven analysis points at the key area within the arc extinguishing chamber are chosen, the variation characteristics of gas pressure, temperature, velocity and Mach number at these points are obtained. Much attention is paid to the comparison of arc performance under the two frequency at current passing zero. The calculation results with 40kA current show that the distributions of gas flow field and the interruption characteristics of arc are related to the power frequency. The increment of gas pressure under 60Hz is faster than that under 50Hz at the cylinder, the temperature at the current zero under 60Hz is higher than that under 50Hz. The simulation results are the arc at 60Hz is harder to extinguish. More improvements should be carried out according to the 60Hz period for meeting the market demand.