Epoxy resin insulation: The influence of nanoparticles on the flashover voltage and possible alternatives for Electrical Machines Insulation

Epoxy resin constitutes a vital insulating element for electrical machine insulation. The present paper deals with the phenomenon of flashover in nanocomposite epoxy resin (with TiO₂ nanoparticles) under the influence of uniform electric fields. As is known, water droplets on insulating surfaces may cause dry zones, local discharges and eventually arcs. Several parameters, affecting the flashover voltage, were investigated, such as water conductivity, droplet volume, number of droplets and the position of the droplets on the samples w.r.t. the electrodes. All the aforementioned parameters affect the flashover voltage. The flashover voltage changes with the percentage of nanoparticles in epoxy resin. It seems that there is an optimum percentage of nanoparticles added to epoxy resin, which gives a higher flashover voltage. Furthermore, comparisons between pure epoxy resin and epoxy resin with nanoparticles showed that the latter presented higher flashover voltages than the former.