Firefly and Standing Still phenomena of free conducting wire-type particles in SF6 under DC voltage

Compared to spherical particles, which are the most prevalent subjects studied by other researchers, free wire-type metallic particles have unique motion phenomena in electric fields under DC voltage, playing an important role in insulation flaw detection of power equipment. However, this is rarely researched sufficiently. Thus, the enclosed experimental chamber and the observation systems are specially designed and motion characteristics of the wire-type particles, with diameters 0.25 mm, 0.4 mm, 0.65 mm and lengths 1 mm, 2 mm, 3 mm, 4 mm, are studied. The results show that probabilities of Firefly and Standing Phenomena increase with lengths of wire-type particles increasing, and the phenomena are more likely to appear on the negative electrode. When the pressure decreases and radiuses of particles fall, probabilities of Firefly and Standing Phenomena increase. In the case of 1mm diameter, there are not any special phenomena under various conditions and the motion of particles is disorder. Lastly, the explanation of experimental phenomena is done in the view of space charge.