Investigation of High-Power Fault Electric Arcs Under 800 V DC Power Supply for the Next-Generation Aircraft

Electric power required in aircraft has significantly increased, causing challenges in power distribution and protection systems. The consequences of electric fault arc occurrence have to be considered because they can be catastrophic. This article reports experimental studies of fault arcs in dc high-power conditions (>500 V/100 A). Four different diagnostics have been performed simultaneously [electrical signals, fast imaging, radiative energy measurements, and optical emission spectroscopy (OES)] for two types of arcs, parallel and series with respect to the load. Very different behaviors have been observed by fast imaging and electrical measurements between the two types of arcs: the parallel arcs present a longer length, are more chaotic, and dissipate more electrical power than series arcs. Radiation energy of the arc in 0.19–20-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m spectral range, measured with two thermopile detectors, represents about 35% of the electrical energy dissipated by the arc and this value does not change according to the experimental conditions in this work. Moreover, optical filters were combined to the detectors to estimate the spectral distribution of the arc radiation in four ranges UV<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub>, UV<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ab</sub>, visible, and IR<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ab</sub>. The total UV contribution is much more important (>60%) than the visible and IR<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ab</sub> ones (15% each) and the UV<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> contribution is higher for series arcs (34%) than for parallel arcs (14%). Emission spectra showed that the most emitting species are the metallic ones (Al, Cu, Ag, and Al<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{+}$ </tex-math></inline-formula>) leading to a strong UV<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> emission, especially for the series arc. Finally, the electrode fall voltages and the mean electric field for series arcs have been estimated and the results are consistent with those of the literature.