Investigation of Arc Dynamic Behavior Change Induced by Various Parameter Configurations for C 4 F 7 N/CO 2 Gas Mixture

This study investigates the feasibility of using a mixture of C 4 F 7 N/CO 2 gases as an eco-friendly arcing medium for high-voltage circuit breakers, comparing its performance to that of conventional SF 6 gas. An existing magnetohydrodynamic (MHD)-based arc model is modified to incorporate the non-recombination characteristics of C 4 F 7 N. The temperature, pressure, and velocity distributions of the arc throughout the whole arcing process are systematically analyzed. First, the differences in multi-physical fields induced by the C 4 F 7 N non-recombination feature are highlighted. The effects of varying the C 4 F 7 N concentration from 4% to 10% in the C 4 F 7 N/CO 2 gas mixture on the arc behavior are also computationally studied. The results indicate significant differences in the arc-extinguishing performance between C 4 F 7 N/CO 2 and SF 6 under identical operating conditions. The potential of using C 4 F 7 N/CO 2 as a viable alternative to SF 6 in circuit breaker applications may need further design efforts to optimize key components such as the driving mechanism and nozzle. Moreover, as the concentration of C 4 F 7 N increases, the gas mixture exhibits improved flow field characteristics, suggesting that a higher volume concentration of C 4 F 7 N enhances the gas’s short-circuit current interruption capabilities.