This paper presents the electrical field stress in new cross-linked polyethylene (XLPE) nanocomposites in case of containing different partial discharges under high voltages. It has been investigated on the effect of variant nanoparticles for controlling the electrical field distribution inside single-core power cables insulation, especially, in case of the presence voids of air, water, and copper impurities with different shapes (cylinder, sphere, and ellipse) inside the insulation of single-core power cables. The electrical field distribution in power cable insulation and inside voids has been measured by the finite element method (FEM). This research success to design different patterns of Crosslinked polyethylene insulation materials for enhancing the dielectric properties within the void and inside the insulator according to the type and concentration of nanoparticles.