The transmission capacity of superconducting AAC Cable is much larger than that of conventional cable. The power transmission capacity of a 10KV three-phase coaxial high temperature AC superconducting cable is greater than that of a conventional 110kV cable, but the transmission loss is only one fourth to one fifth of that of a conventional cable, which is very suitable for power supply in high load density areas. However, due to the great difficulty of project implementation, at present, the above application scenarios are still blank in China and even in the world.
The superconducting cable laid this time passes through the busy roads, subway areas and core business districts in the central urban area of Shenzhen. The laying environment space is narrow. There are special complex working conditions such as 24.2m vertical drop, more than 10 turns less than 90 degrees, short-span S-shaped corners and staggered height of transmission pipelines. There is almost no precedent experience to follow. It is a typical “small corridor” of complex transmission in large cities, Even laying conventional cables is challenging.
In the face of such special and complex working conditions, in order to ensure the smooth completion of superconducting cable laying, the superconducting cable project team of Shenzhen Power Supply Bureau has conducted dozens of field surveys and discussions in the past three months, and formulated a special research scheme of “remote simulation laying + on-site pre laying”. The project team built a simulation site at the location of the manufacturer, restored various special and complex working conditions, carried out many simulation laying drills, obtained a large amount of valuable data, accumulated on-site experience and laid a solid foundation for on-site laying. In the project site, analog cables of the same size and weight are pre laid twice, which provides the most direct reference for formal laying.
During the laying process, in addition to the conveyor and winch required for conventional AAAC Cable laying, the project team has developed special auxiliary guidance, turning radius limit protection, nozzle center positioning, well shaped conveying wheel set and other laying tools and instruments to ensure the safe and reliable laying of superconducting cable body.
Next, the project will enter the installation, test and commissioning stage of superconducting cable accessories, supporting low-temperature refrigeration system, measurement and control protection system, etc. When the project is put into operation, it is expected to “package” solve many problems and challenges such as the difficulty of power grid construction land in large cities, the continuous growth of power grid load demand and the saturation of urban transmission and distribution corridors, so as to provide a new scheme for solving the problem of regional power supply with high load density in mega cities around the world
Other media reports:
The first 10kV three-phase coaxial high temperature AC superconducting cable in China has been laid
Xinhua news agency, Shenzhen, July 30 (reporter Wang Feng) – the reporter learned from the Shenzhen Power Supply Bureau of China Southern Power Grid on the 30th that the first 10kV three-phase coaxial high-temperature AC superconducting cable in China was laid in Shenzhen on the 28th, laying the foundation for the first demonstration project of this type of superconducting cable to be put into operation within the year. It is expected to “package” solve the difficulty of power grid construction land and the continuous growth of power grid load demand in big cities There are many problems and challenges such as the saturation of urban transmission and distribution corridors.
It is reported that the project is a major science and technology project of China Southern Power Grid Corporation. It is developed by Shenzhen Power Supply Bureau of China Southern Power Grid and connects 220 kV Binhe substation and 110 kV Xinghe substation in Futian central area of Shenzhen. The cable length is 400 meters. It will supply power to important loads such as Shenzhen landmark Ping’an building.
High temperature superconducting power transmission refers to the use of the superconducting properties of superconducting materials to make the power transmission medium close to zero resistance and the power transmission loss close to zero in the liquid nitrogen environment close to minus 200 ℃ relative to absolute zero, so as to realize high-capacity power transmission at low voltage level. A 10KV three-phase coaxial high temperature AC superconducting cable has the power transmission capacity equivalent to a conventional 110kV cable.
It is understood that at present, most domestic superconducting ACSR Cable demonstration projects are experimental in nature, and the importance level of line load is low. The demonstration project plans to apply superconducting cable to the high load density power supply area in the city center to supply power to important loads, which will be a big test for the application of superconducting cable.
Next, the project will enter the installation, test and commissioning stage of superconducting cable accessories, supporting low-temperature refrigeration system, measurement and control protection system, etc. When the project is put into operation, it will provide a new scheme and model for solving the power supply problem in high load density areas of mega cities.