Partial discharge measurements during the degradation of nanocomposite twisted pair specimens

Several electrical aging tests have been carried out on twisted pair specimens prepared by winding wires having conventional or nanostructured enamel insulation. The conventional enamel is polyamide-imide, while the nanostructured enamel is a polyamide imide - silica nanocomposite. The tests have been performed applying sinusoidal voltage at two different frequencies. The partial discharge (PD) signals acquired during the aging tests have been post-processed to define, in the case of the conventional enamel, a reliable parameter useful to implement an empirical prediction model. In this way, after a short PD activity monitoring time, the residual duration of twisted pair specimens can be computed.