CROSS-BORDER CABLE SMART TRADING PLATFORM

　　On September 28, China's first self-developed new type of superconducting cable was put into use in Shenzhen. This is also the world's first superconducting cable applied in the central area of a super-large city, marking that China has fully mastered the design and manufacture of new superconducting cables. , the key core technology of construction.

　　The new superconducting cable is only 17.5 cm in diameter, 400 meters long, and has a transmission capacity of up to 43 MVA, which is equivalent to meeting the electricity demand of four high-speed railways with a speed of 350 kilometers per hour at the same time, achieving five times the transmission capacity of conventional cables. It can bring high-reliability power supply to Shenzhen Ping An Financial Center, the tallest building in the Guangdong-Hong Kong-Macao Greater Bay Area.

　　As a major scientific and technological project of China Southern Power Grid Corporation, this project is a powerful measure to deeply implement the innovation-driven development strategy and promote scientific and technological self-reliance and self-reliance. It not only realizes 100% localization of key equipment, but also provides power supply for the high-load density areas of super-large cities around the world. The problem provides new solutions.

　　High-temperature superconducting power transmission technology is known as the next-generation power transmission strategic technology, which has the advantages of low line loss, large transmission capacity, small corridor footprint, and environmental friendliness. This technology takes advantage of the conductive properties of superconducting materials, so that the loss of electricity in the process of low-voltage transmission is almost zero. The transmission capacity of superconducting cables is much larger than that of conventional cables. The power transmission capacity of a 10kV three-phase coaxial high-temperature superconducting AC cable is greater than that of a conventional 110kV cable, but the transmission loss is only 1/4 to 1/4 of that of conventional cables. 5. It is very suitable for power supply in areas with high load density.

　　In recent years, the power supply in the central areas of super-large cities all over the world is facing challenges. The load demand in the central areas of the cities continues to grow, the requirements for “double reduction” of energy consumption are increasing year by year, the urban corridors are saturated, and the difficulty of using land for power grid construction has been exposed year by year. Shenzhen is the city with the largest power load density in China, and the load density of its central business district is even more "peak on the peak". The project "package" solves the problem of high power supply reliability, high load density, high power quality, and limited land resources. real problems.

　　"If the existing power supply methods are used, it is very difficult to supply the important loads in the central area of Futian, especially the newly added loads, and to use conventional technologies to achieve capacity expansion, which is very difficult in Shenzhen, where land is expensive." Innovation and Digitalization Department of Shenzhen Power Supply Bureau General Manager Lv Zhining introduced that while 10kV superconducting cables can meet the power supply demand, it can reduce the use of high-voltage cables in the urban power grid, simplify the grid structure, reduce the construction of 110kV substations, and save 500 square meters of land.

　　The superconducting cable developed and put into production this time adopts a three-phase coaxial configuration, which is the superconducting cable with the most compact structure, the least amount of strip material, and the most difficult research and development. After 4 years, the project team has achieved major breakthroughs in key technologies such as the overall design and manufacture of superconducting cable systems, and the development of domestic large-capacity GM refrigerators through independent innovation, and achieved 100% localization of key equipment, filling domestic technology. blank.

　　The cost of superconducting cables is reasonable, and there is a possibility of sustainable promotion. It is understood that the cost of superconducting tape accounts for about 50% of the cost of the entire superconducting cable, and the three-phase coaxial superconducting cable saves nearly half of the superconducting tape compared to other superconducting cables.

　　In addition, the superconducting cable put into operation this time uses superconductors that can be cooled in a liquid nitrogen environment instead of conventional copper-aluminum conductors for power transmission. Liquid nitrogen is a relatively simple and inexpensive cooling medium, so high temperature (about 70°C higher than absolute zero, so called "high temperature") superconductivity has important application value. In order to solve the "stuck neck" problem of the low-temperature refrigeration equipment of superconducting cables, the project team successfully developed the nationally produced large-capacity GM refrigerator for the first time in the country, and realized the online "plug and play" of the refrigerator, which can make the superconducting cable in the subzero temperature. It can maintain high reliability for a long time in a liquid nitrogen environment of 200 °C.

　　The reporter learned from the innovation management department of China Southern Power Grid Corporation that compared with conventional technologies, the high-temperature superconducting demonstration project put into operation has basically reached the economic equilibrium point. In the next step, China Southern Power Grid Corporation will further increase investment and actively Promote the construction of scientific research and demonstration projects for superconducting applications in distribution networks.