Electrical Arc Fault Particle Size Characterization

Report on high energy arcing fault experiments :

“… Particle analysis indicated the oxidation characteristics from this series of experiments were similar to the results from the bench-scale experiments [2].…”

“…Degree of oxidation in collected particles was quantified by energy dispersive spectroscopy x-ray analysis (EDS). Like prior small-scale (6.9 kV, 10 kA, 4 ms [2]) arc fault experiments, a bimodal particle size distribution was observed including nanoscale particles displaying full oxidation (O:Al ratios near 1:1) and micrometer-scale particles displaying partial oxidation (O:Al ratios of 0.24-0.74:1). An example of this bimodal distribution is shown in Fig.…”

“…20, fully oxidized aluminum oxide ceramic displayed an aluminum-to-oxygen peak ratio of approximately 1.04:1, which was utilized to estimate relative degree of evolved aluminum particle oxidation. In prior lab scale arc experiments conducted at a nominal 6.9 kV, particle characterization was discussed in detail [2]. Two particle types were identified: small size particles (10 nm to 50 nm particle size) which appeared to be fully oxidized (Al:O ratio near 1:1) and larger 2 µm to 25 µm particle size aluminum spheres, which appeared to be 10 percent to 70 percent oxidized (Fig.…”

Report on high energy arcing fault experiments :

“…The experiments are designed to complement small-scale arc experiments that were performed at SNL in 2018 and 2019 [12]. The small-scale experiments were limited in the amount of energy that could be delivered to the arc.…”

“…In addition, three-phase faults were performed instead of single-phase to ground faults. The small-scale experimental results are documented in SAND2019-11145, "Electrical Arc Fault Particle Size Characterization [12]. "…”