Interfacial microstructure and withstand voltage of polyethylene for power cables

In order to increase the electrical breakdown strength and treeing inception voltage of cross-linked polyethylene (XLPE) insulated power cable, surfactant in combination with titanate coupling agent, as an additive, has been mixed with the semiconducting layer, which is surrounded by polyethylene insulation, to chemically improve the dielectric properties of polyethylene interface. By means of infrared and X-ray diffraction spectra analyses, a change in the crystalline orientation angle and the density of polyethylene is observed inside the improved polyethylene interfacial layer. Additionally, it is assumed that a thin diffusion layer is formed, that results in a decrease in the electric field stress on the polyethylene interface and then an increase in the withstand voltage of polyethylene.