On April 30, 2020, China's first 35 kV kilometer-level high-temperature superconducting cable demonstration project officially started construction in Shanghai. This is the first commercial application of high-temperature superconducting cable power transmission technology in China. The localization rate of the core technology of the project has reached 100%, and it has filled a number of gaps in international standards, marking that China has taken a leading international position in the field of high-temperature superconducting power transmission.
On October 22, 2020, China`s first 35 kV kilometer-level high-temperature superconducting cable demonstration project built by the State Grid of China officially launched the cable pull test link, and collected the first batch of high-temperature superconducting cables in complex environments. Key data such as traction and lateral pressure during laying confirmed the feasibility of the construction plan.
High-temperature superconducting power transmission refers to the use of the superconducting characteristics of superconducting materials in a liquid nitrogen environment close to minus 200 degrees Celsius relative to absolute zero, so that the power transmission medium is close to zero resistance, and the power transmission loss is close to zero. So as to realize large-capacity power transmission at low voltage levels.
High-temperature superconducting power transmission is one of the most revolutionary engineering technologies in the current power industry. High-temperature superconductivity uses the characteristics of superconducting materials in a liquid nitrogen environment close to minus 200 degrees Celsius relative to absolute zero to make the power transmission medium close to zero resistance and power transmission close to zero loss, thereby achieving low voltage levels Of large-capacity power transmission.
High-temperature superconducting power transmission has low loss, large capacity, small size and no pollution. Generally speaking, 35 kV superconducting cable is equivalent to the transmission capacity of traditional 220 kV cable, which can replace 4-6 traditional cables of the same voltage level, saving 70% of the underground pipe gallery space, greatly reducing construction costs, and very suitable The large-capacity electric energy is directly transmitted to the central area of the city.
The construction of the localized kilometer-level high-temperature superconducting cable demonstration project carried out by SHGJ Superconducting Technology Corporation and China Power Grid will provide a feasible solution to the contradiction of the "overheating" of the urban central power grid load. The "small channel and large capacity" transmission mode will help build a highly reliable, environment-friendly, and resource-friendly urban energy Internet in the central area of Shanghai.
This high-temperature superconducting cable demonstration project is one of the results of a strategic cooperation in the science and technology industry jointly carried out by the State Grid and Shanghai. The project site is located in the Xujiahui area in central Shanghai. It connects two 220kV substations with a total length of about 1.2 kilometers. It is expected to be completed and put into operation at the end of the year. By then, it will become the world's largest transmission capacity and longest distance fully commercial operation 35kV. Superconducting cable engineering.
It is understood that the core of the superconducting cable laid in the demonstration project uses twenty or thirty 0.4 mm thick second-generation superconducting tapes. From design to manufacturing, materials are fully localized. In addition to having completely independent intellectual property rights in equipment, the demonstration project also incorporates innovative breakthroughs in the entire pipeline laying process and system operation and maintenance stability, and has led the formulation of multiple technical standards internationally.
The kilometer-level high-temperature superconducting cable demonstration project is the product of the deep integration of China's superconducting material application and the development of power grids. This industrial integration model has strongly promoted the leap from experiment to practical use of Chinese superconducting materials.