Views: 0 Author: Site Editor Publish Time: 2024-06-20 Origin: Site
Engineers have officially powered up a 35 kV transmission capacity superconducting cable in Shanghai, China. Reaching its full-load capacity during a test, this, China.org.cn claims, is the world’s longest kilometer-level superconducting cable. The cable, which is 3/4-mile (1.2 km) in length, is unique in that it has been put into operation in an urban core and installed entirely in ducts. This makes it, Chinese sources claim, to be the only cable of its kind globally.
One-of-a-kind
Superconducting power transmission cables use superconductivity to transmit electricity with almost no losses. The principle of superconducting materials is to reduce the resistance of power transmission to almost zero in low-temperature liquid nitrogen. One superconducting cable can transmit the same amount of power as four to six conventional cables at the same voltage level, thus saving about 70 percent of underground pipe space.
The quoted cable voltage is towards the higher end of medium voltage ranges for urban and semi-urban applications. Superconducting cables in this range might operate at 15 kV, 25 kV, or 35 kV. This range is typical for distribution networks. Cities like Shanghai primarily use superconducting cables for their distribution networks. This range is suitable for the density and power needs of urban areas. But, what is unique about this cable is its length and duct installation.
The new demonstration project spans 3 quarters of a mile (1.2 km) between two 220 kV substations in Xuhui District, central Shanghai. Its design current is 2,200 amperes. The cable is “the result of two decades of efforts by engineers at Shanghai Electric Cable Research Institute (SECRI) under Shenergy Group, an enterprise which has specialized in electric cable over the past 60 years and which spearheads the superconducting transmission industry,” explains China.org.cn.
“If superconducting cables are widely used, the problems of high electricity density and limited space in super-large cities like Shanghai can be solved,” said Huang Chongqi, a member of the Chinese Academy of Engineering and an expert in superconducting cables. The Shanghai Electric Cable Research Institute (SECRI) team believes that independent innovation is essential for pioneering this frontier industry.
“Our self-design helped reduce the cost of superconducting raw materials, once monopolized by foreign countries, by nearly two-thirds,” said Huang, a senior SECRI engineer.
“The detection and isolation of weak electric signals in the superconducting cable system was a world-class technical challenge. SECRI engineers worked independently to acquire key test data, which effectively enhanced their standard-setting capability at the world’s first international standard conference for superconducting cables,” explained China.org.cn.