Research progress of environment-friendly HVDC power cable insulation materials

With the development of high voltage high voltage (HVDC) transmission technology, HVDC cable power transmission will play an important role in the future electric power transmission. The key problem in HVDC cable power transmission is the breakthrough in HVDC cable insulation materials. So it is important to develop environment-friendly HVDC cable insulation materials to overcome the disadvantages of traditional cross-linked polyethylene (XLPE), such as non-recyclable, limited working temperature and complicated processing technology. In order to promote the research and development of environment-friendly HVDC cable insulation materials, the progresses and key technologies of environment-friendly HVDC cable insulation materials are reviewed. It summarizes the research progress of several polyolefin environment-friendly insulation materials for HVDC cables and three modification methods of polyolefin materials, blending modification, nano-doping modification and chemical grafting modification. The advantages of environment-friendly HVDC cable insulation materials are compared with those of traditional cross-linked polyethylene. It revealed that the thermoplastic polyolefin, especially polypropylene based environment-friendly HVDC cable insulation material shows good application prospect, which can effectively improve the working temperature of DC cables and simplify the processing technology. In the development of HVDC cable insulation material, more attention should be paid to the high temperature performance of the materials to exert their advantages of the material and improve the operating temperature of HVDC cables. At the same time, aging performance of environment-friendly insulation materials should be studied simultaneously.