Frequent operation of filter field circuit breakers often induces particle discharge faults. Analysis suggests this may be related to the electric and flow fields generated after switching operations. When the breaker opens

it often presents a complex electric field with superimposed AC and DC components. Moreover

frequent breaker operations produce airflow that can significantly affect particle motion. We established a finite-element simulation model of a 750 kV filter field circuit breaker and obtained the airflow distribution patterns during operation. It was found that switching operations generate high-speed airflow of hundreds of meters per second at the nozzle and low-speed airflow below 3 m/s near the enclosure. Furthermore

by calculating the motion trajectories of metal particles in different regions during breaker operations

it was observed that

during closing

particles on the power supply side

intermediate floating section

and load side exhibit similar motion characteristics. During opening

however

particles on the floating section and load side move much more intensely than those on the power supply side. Further observation revealed that particle motion on these two sides is considerably more violent during opening than during closing

with the maximum flight height per unit time reaching approximately 10 times that during closing. By further analyzing the coupled effect of electric and flow fields during opening and examining the influence of airflow on metal particles in the three regions

results indicate that switching-generated airflow may cause centimeter-level horizontal displacement of metal particles near the enclosure within one second. Under frequent operations

this likely enables particles to migrate into high electric field regions

producing non-negligible effects.