In order to improve the performances of are-extinguishing lightning protection of intermediate and low-voltage power network lines and to reduce the trip-out rate

we developed a kind of self-expanding stream of arc-extinguishing lightning protection gap device

which is effective in inhibiting frequency arc. The gap

which can precisely position lightning discharge path

forces the arc column to form a segmentation. While it generates high pressure from the expansion of high-speed air

which strongly inhibits the development of transient power frequency wheeling arc

and ultimately extinguishes the arc. The formation mechanism of self-expanding stream was studied and self-expanding stream coupling power frequency arc mathematical mode was founded. A CFD software FLUENT was used to analyze the self-expanding stream airflow arc extinction. Moreover

experiments on arc-extinguishing lightning protection gap device were conducted

and the detailed process of arc extinguishing were recorded by using high-speed cameras. The actual operating results of the device on 10 kV distribution network lines were analyzed. The results show that the frequency freewheeling arc can be quickly extinguished by the self-expanding stream impaction

and lightning protection gap can significantly reduce the lightning trip-out rate to protect the safe and normal operation of the power grid with good usability.