Research on Pressure Characteristics of Arc Ignited by Metal Wire in Closed Container

Using mental wires to generate electric arc is one of common means. The wire will be accompanied by shock waves at the moment of electrical explosion; In addition, the arc thermal effect will also lead to the rise of pressure inside the closed container. In this paper, two physical processes of wire electric explosion and arc thermal effect are introduced firstly. Taking the pressure wave in transformer oil as an example, the influence of the two physical processes on the pressure characteristics of the container filled with liquid is analyzed. In order to further study the pressure characteristics of arc of the container filled with air, an short-circuit test platform at 50 HZ was built. Three groups of short-circuit tests were carried out by controlling different current peaks, and the arc burning time was 50ms. The results show that the pressure increases slowly with time, and the higher the current peak is, the greater the pressure increment is. With the increase of current, there is no shock wave, and the process of pressure rise corresponds to the arc burning time, so it is determined that the main reason of pressure rise is the thermal effect of arc. The research content of this paper clarifies the physical process for the subsequent pressure rise calculation of short-circuit arc of the cable intermediate joint in the explosion-proof box.