December 5th, it was learned from the Power Science Research Institute of Guangdong Power Grid Company, Southern Power Grid (hereinafter referred to as the Power Research Institute), that the world's first 110 kV grafted modified polypropylene insulated eco-friendly cable, developed under the leadership of the institute, has successfully passed all type tests and inspections, with all performance indicators meeting the product design requirements. This marks the successful development of the first high-voltage grade grafted polypropylene eco-friendly cable internationally, with original technology and independent intellectual property rights mastered by China.

Earlier this year, the 10 kV and 35 kV grafted polypropylene eco-friendly cables developed under the leadership of Southern Power Grid Company were successively put into engineering application. However, due to the more stringent requirements for material cleanliness and cable production line modifications for high-voltage grade grafted modified polypropylene insulated cables, the finished cables had to meet indicators such as micropore impurities and eccentricity, making process control more difficult after the increase in insulation thickness.

To tackle the research and application of higher voltage grade eco-friendly cables, Southern Power Grid Company formed a cross-unit, cross-disciplinary joint research team in collaboration with Tsinghua University, Sinopec, Zhongtian Technology, and other industry-academia-research-application units.

According to Yu Xin, a cable expert from the Transmission Institute of the Power Research Institute, the team optimized the cable material formula and preparation process. For the first time internationally, advanced aqueous phase suspension grafting technology was used to structurally optimize and control the performance of polypropylene materials. Key equipment such as the extrusion and cooling for the 110 kV cable production was modified, solving problems such as three-layer co-extrusion and internal stress control of polypropylene insulated cables, and breaking through key technologies such as the polypropylene cable material system, industrial preparation, and cable extrusion process.

After type test verification, the cable system's conductor can operate at a long-term temperature of 105°C. Compared to traditional cross-linked polyethylene cables with a long-term operating temperature of 90°C, the current carrying capacity can be increased by more than 10%, effectively solving the bottleneck problem of some cable line transmission capacity. It provides important support for the green and economical operation of medium and high voltage cables in China's power grid and further verifies the grafting modification technology of polypropylene materials and the processing performance of polypropylene cables, laying the foundation for the development of higher voltage grade eco-friendly cables.

Peng Xiangyang, a senior professional technical expert at Southern Power Grid Company, stated that this new type of eco-friendly cable is produced using chemically modified polypropylene insulation materials. It has characteristics such as low production energy consumption, high operating temperature, no cross-linking by-products, and recyclability. It possesses good socio-economic benefits and promotional value, aligns with the green and low-carbon development trend of new power system equipment, and is one of the important technical directions in the cable industry.