Partial discharges of nonwoven nanofibers composite

A promising technology of nanofibrous composites is studied nowadays as an alternative method to the well-known dielectric nanocomposites filled by various nanofillers like a metallic oxides, alumina, silica, carbon nanofibers or nanotubes. All of these nanofillers are known, more or less. The use is to improve some of the electrical, mechanical and thermal properties of nanocomposites. Unfortunately, its expensiveness and tendency to agglomeration remain as their main disadvantage. In the contrary, the nanofibers can be applied as a nonwoven fabric over the surface of the composite with no tendency to create the cluster agglomeration as the nanocomposites with nanoparticles. It was prepared experimental specimens of nonwoven nanofibers composites based on the modification of commonly used three-component mica-based electrical insulating material (epoxy, glass fibers and mica). The modification of these, well known, mica composites was done by incorporation of the nonwoven nanofibers layers (1, 2 and 3) to its structure always with different area density (1, 3 and 5 g/m2) of the nanofibers. The tested material was delivered in the form of resin-rich sheets on which the layers of the nanofibers made from Polyamide 6 were applied and specimens were subsequently cured using typical resin rich curing process. The influence of prepared modifications on the partial discharge characteristics and magnitudes of the resulting nanocomposites was studied. Partial discharges results show differences between the specimens' variations depending on nanofibers presence, the number of layers and surface density of nanofibers. The decreasing of the partial discharge activity is recognisable when the nanofabrics is incorporated into the composite. The obtained results proved that the nonwoven nanofibers based on Polyamide 6 seem to be a perspective material with certain resistance to partial discharge activity. © 2016 IEEE