Analysis of Airflow Field During Arc-Firing Process of Pressurized Gas Circuit Breaker Based on Finite Element Simulation

In the context of increasing voltage level of power system and increasingly complex energy structure, high-voltage circuit breakers are crucial to ensure stable operation of the system. Due to the complexity of high-voltage circuit breaker experiments and high resource consumption, simulation analysis has become an important means to study its performance. In this paper, the finite element simulation method is applied to simulate the breaking process of 550KV pressurized gas SF6 circuit breaker under 63KA T100a working condition. By establishing a two-dimensional axisymmetric MHD model, simplifying the dynamic mesh setup with the relative motion method, and using the finite volume method to numerically simulate the airflow field in the arc-firing process. We focus on comparing and analyzing the pressure and temperature data at the nozzle at the moment of current peak and the moment of current zero. The results show that the pressure and temperature inside the arc extinguishing chamber at the moment of current zero is significantly lower than that at the moment of current peak, and the velocity inside the arc extinguishing chamber is reduced and the turbulence is weakened, which indicates that the circuit breaker has good arc extinguishing performance and can effectively cut off the short-circuit current. This study provides strong support for the subsequent experiments of this circuit breaker and helps to shorten the product development cycle.