Simulation Study on Breaking Ability of 550 kV SF6 Circuit Breaker with First Opening Coefficient 1.5

This article is based on the arc extinguishing chamber of the X-type tank circuit breaker (hereinafter referred to as the arc extinguishing chamber), and simulates the electric field between the fracture surfaces under three test conditions of short, medium, and long arc with a first pole coefficient of 1.5. At the same time, the airflow field is simulated under these three conditions, and the combination of electrostatic and airflow fields is analyzed to evaluate the breaking ability of the circuit breaker from the perspective of dielectric recovery performance. According to the requirements of the arc extinguishing chamber structure and simulation mathematical model, simplify the model and obtain important airflow field parameters of the circuit breaker during the breaking process through simulation calculations. Comparing and analyzing the calculation results, it is shown that the arc extinguishing chamber can meet the system requirements under three operating conditions of short, medium, and long arc, and has good breaking performance. Afterwards, the circuit breaker successfully passed the test at the experimental station, which also confirmed the conclusions of the simulation and confirmed the correctness of the simulation calculation method, adding great persuasiveness to the guidance of simulation methods for the structural design of the circuit breaker in the future.