Investigation of DC arc in hydrogen and air

With the increased power capacity of more/all electric aircraft, the current was up to hundreds of amperes and the supply voltage increased. Large interrupting capacity, compact size and light weight are the requirements of aviation switch in the future. According to hydrogen has its own advantage of light weight, high speed of molecular motion, high thermal coefficient, and strong deionization effect, which is helpful for extinguishing DC arc. In order to confirm this, in this paper, hydrogen is used for arc-quenching medium, and the current interruption experiments were carried out in prototype hydrogen and air switches. The experiment was performed on double contact structure which materials were Cu, with a contact diameter of 11mm and a contact gap of 1.5mm, and a DC circuit was established. To find out the relationship between the arc in hydrogen and air, the arc characteristics of hydrogen/air DC arc were investigated at different current, such as 50A~1.8KA etc. and also the cut-off time. Furthermore, phase transition of DC arc and the characteristics of arcing were researched. At last, the experimental results were analyzed; it was shown that the hydrogen arc has short arc duration, high electric potential gradient and high interruption capacity.