A major breakthrough in the research and development of 500 kV flexible DC cable accessories

December 22, 2021

2021 Power New Era Forum
Polaris Transmission and Distribution Network News: On September 1, as the 500kV flexible DC cable accessory designed and developed by the European Institute of Global Energy Internet (European Institute) has passed all type tests, the Global Energy Internet Institute Co., Ltd. A major breakthrough has been made in the research and development of another key equipment in the field, and it has mastered the key technology of environmentally friendly flexible DC cable accessories for the 500 kV silicone rubber technology route.

my country is the world's largest cable manufacturer, but core technologies such as high-voltage cables have always been constrained by others. At present, the insulation materials and accessories of domestic high-voltage cables basically rely on imports. With the increasing demand for large-scale offshore wind power flexible DC grid connection, the technical bottleneck of high-voltage cable materials and accessories has become increasingly prominent. State Grid Co., Ltd. vigorously implements the innovation-driven development strategy, organizes scientific and technological research teams to work hard on key technologies such as high-voltage cables, deploys a special project of "±500 kV flexible DC submarine cable key technology research" to support the development of core 500 kV DC cables and accessories Equipment and technology research. The Joint Research Institute undertook the "Key Technology Research on DC Cable Accessories Development" project, and carried out the research and development of 500 kV DC cable accessories (including terminals and connectors).

DC cable accessories are the key equipment for the interconnection of high-voltage DC cables with converter stations and cables. Its development involves technical problems in materials, machinery, manufacturing, and installation, and is one of the main bottlenecks in the development of high-voltage DC cable technology. At the same time, in order to meet the increasingly stringent requirements for green environmental protection, the Joint Research Institute is aiming at the research and development of the technical route of cable accessories based on silicone rubber materials. Compared with EPDM technology, this technology has the advantages of green and environmental protection, but it also increases the difficulty of design and process. The application of this technology in 500 kV voltage level equipment has not been broken internationally.

Based on the technologies of 220kV AC and ±320kV DC cable accessories, the European Institute has carried out a large number of structural design, simulation analysis and structural optimization work for 500kV cable terminals, and jointly tackled key problems with domestic R&D and manufacturing teams. The cable accessory structure process design, test terminal development and overall test work were developed, and the first silicon rubber-based 500 kV DC cable accessory and 500 kV fast plug-in DC test terminal were developed.

The European Institute has created a brand-new technical route, breaking the conclusion that foreign manufacturers' silicone rubber technology is not suitable for 500 kV high-voltage DC cable accessories. As an important part of the company’s scientific and technological innovation system, the European Institute will continue to give full play to the advantages of talents, be mindless, overcome difficulties, solve the problem of “stuck necks” in key areas of application foundation and strategic forward-looking technology research, seize the commanding heights of innovation, and build China International leading energy Internet companies contribute new wisdom and create new performance.