In order to solve the problem of lightning flashover caused by DC transmission line trip

we established a high-speed airflow velocity shock model

analyzed the force situation of DC arc motion

and derived the extinguishing conditions of DC arc Moreover

by analying the model and using the FLUNET software

we simulated and analyzed the arc-extinguishing process in high speed flow under ideal conditions

and conducted arc-extinguishing tests in high voltage laboratory conditions. The research results show that the extinguishing time of simulation is 1.2 ms

while the extinguishing time of test is 1.7 ms. Because the arc simulation can not simulate the real conditions

there is a 0.5 ms error between the arc extinguishing time obtained by simulation and test

but both of them are less than the action time of relay protection. The results verify the effectiveness of high-speed airflow arc-extinguishing anti-thunder gap and DC arc extinguishing.