Research Status of Polyethylene Insulation for High Voltage Direct Current Cables

Abstract

Polyethylene materials has been widely used in HVDC cable insulation because of its excellent dielectric properties. During the operation of HVDC cable, the conductivity changes of insulation material caused by temperature gradient and the space charge accumulation under DC electric field, resulting in the distortion of electric field inside insulation material, which is the most serious problems of the polyethylene insulation for HVDC cables application. In this paper, the research progress of polyethylene insulation for HVDC cables was reviewed. The dielectric properties and the improvement mechanism of the modified polyethylene materials were analyzed. And the development trend of HVDC polyethylene insulation materials was prospected at the end of the paper. The results show that nano-doping can effectively inhibit the accumulation of space charge in polyethylene insulation and improve its temperature dependent conductivity characteristic. It is possible to improve the dielectric property of XLPE insulation by blending modification. Adding voltage stabilizer can improve the property of resisting electrical tree in polyethylene insulation, which has a good prospect for application. Super-clean polyethylene material is the foundation and focus of the research on HVDC cable insulation. The summary of these researches can provide reference for the development of polyethylene insulation materials for HVDC cables.