Study on LDPE Optimization for Domestic HVDC Cable

Abstract

The performance of low-density polyethylene (LDPE) restricts the development of cable insulation in China. Compared with imported LDPE, the performance of domestic LDPE has a great space to improve. The imported LDPE (A and B) used in this paper were obtained by extraction. The samples (1#, 2#, 3#) of domestic materials were taken from LDPE materials at different stages of the process optimization. DC breakdown strength, electrical conductivity and mechanical properties of domestic LDPE and imported LDPE materials were carried out. The results show that with the continuous optimization of domestic LDPE material, the breakdown characteristics of the material are greatly improved. However, compared with imported LDPE material, the breakdown field strength at low temperature is still lower than that of imported materials, and the repeatability of the breakdown test still needs to be improved. The conductivity of domestic LDPE is close to that of imported material. The tensile strength and elongation at break of domestic LDPE material are slightly lower than that of imported material. Therefore, it is necessary to continue to optimize the structure of domestic LDPE materials to improve their breakdown characteristics and mechanical properties.