Characterization of High Frequency Arcs under Atmospheric Pressure for Different Electrode Gaps

There is a drive in the aviation industry towards more-electric aircraft (MEA) to replace fuel-driven airplane engines with more-electric power systems and improved efficiency. This requires a higher on-board electric power generation and a higher operating frequency to maintain a compact power system architecture. However, higher operating voltages in aeronautical environment, coupled with the need to maintain compact design, increase the risk of arcing. Arc faults are characterized by their high current magnitude which could lead to a significant release of energy that may damage the equipment as well as the adjacent components. The length of the electrode gap across which the arc ignites is one factor that determines the arc severity. This paper investigates the arc over a range of electrode gaps from 2.5 to 100 mm under atmospheric pressure and within a high-frequency circuit. For gaps ≤ 40 mm, the arc voltage increases as the arc cools down, whilst for gaps ≥ 50 mm the arc voltage decreases. The results conclude that longer gaps in this underdamped circuit setup exhibit a lower arc voltage with lower arc current, which is different to the arc behavior observed in shorter electrode gaps.