Influences of Arcing Time and Initial Pressure of the Puffer Chamber on Asymmetric Short-Circuit Current Interruption Performance of High-Voltage SF6 Circuit Breakers

With the continuous increase in grid capacity and the rise in the time constant of the DC component of short-circuit currents in power systems, the hidden dangers of insufficient interrupting capability of circuit breakers have become increasingly prominent. Therefore, it is crucial to study the factors affecting the interruption performance of circuit breakers. The article establishes a physical arc simulation model based on the internal structure of high-voltage SF6 circuit breakers, and investigates the effects of the time constant of the DC component of short-circuit currents, arcing time, and initial pressure of the puffer chamber on the interruption performance of the circuit breakers. The results show that increasing the arcing time and initial pressure of the puffer chamber facilitates circuit breaker interruption, while an increase in the DC component tends to lead to interruption failure. These findings provide a theoretical basis for improving the capability of high-voltage circuit breakers to interrupt asymmetric short-circuit currents.