The process of localization of insulating materials for ultra-high voltage cross-linked cables has been accelerated. 

110kV class crosslinked insulation and shielding materials have been implemented in batch domestic applications; 

220kV class crosslinked insulation and shielding materials have been demonstrated; 

330kV class crosslinked insulation and shielding materials start demonstration application. 

(1) Domestic development of 35kV and below polypropylene insulation and shielding materials, batch application in distribution networks, new energy and other fields has been more than 3 years. Demonstration application of 110kV grade polypropylene insulating material and shielding material in 110kV line of China Southern Power Grid. 

(2) The working temperature of the imported HVDC insulation material is increased from 70℃ to 90℃. The development and demonstration application of HVDC insulation materials have been carried out in China. 

(3) The improvement and upgrading of low-smoke halogen-free flame retardant sheath and fire-resistant cable materials can meet the comprehensive performance of flame retardant and fire-resistant, mechanical and electrical.