Experimental Measurements of Partial Discharge Activity within LDPE/TiO2 Nanocomposites

The presence of impurities, voids or gas bubbles during the manufacturing process of insulating materials of power cables leads to electrical degradation in the form of partial discharges (PDs). This paper aims to investigate the influence of incorporated titanium dioxide (TiO2) nanoparticles on the statistical parameters of PD activity within low density polyethylene (LDPE) matrix through using the solvent casting method. The surface morphology of synthesized LDPE/TiO2 nanocomposites was characterized by field emission scanning electron microscopy (FE-SEM). Then, the internal discharge measurements were performed using the traditional needle-plane configuration with the help of phase resolved partial discharge analyzer (PRPDA). This technique is used to analyze the statistical characteristics and feature of PDs with respect to the phase angle of applied voltage. It is found that the PD activity of all LDPE/TiO2 nanocomposite samples that represented by discharge magnitude, inception voltage, extinction voltage, and PD generation rate was enhanced compared to that of the pure LDPE. This was explained considering the effect of TiO2 nanoparticles in trapping process and initial electron generation inside the insulation material. Also, governing mechanisms for positive and negative cycle of PD activity were discussed.