The world's first high-temperature superconductor (HTS) cable that supports the major power grid of a mega city enters the final stage after 2 years of efforts. On November 3, after the demonstration project was fully completed, the length of the superconductor cable was sharply increased from several hundred meters to over 1 km, and key problems were resolved. It indicates that the key technical project on the construction of a new power system in China enters the final stage of completion and commissioning. In light of the project schedule, it is expected to be put into service in conjunction with the power system by the end of this year. 

The cable is the result of 20 years of arduous efforts made by scientific researchers of Shanghai International Superconductor Technology Co., Ltd. in Baoshan District in relation to key materials, cable structure, key components and pipe-jacking construction. 

Shanghai International Superconductor Technology Co., Ltd., located in Baoshan Hi-tech Industrial Park, is a company engaging in the design, R&D, production & inspection, engineering application and technical consulting of superconductor cables. It is capable of continuously producing 500m long HTS cables that withstand low temperatures. It also provides industry and user-oriented technical consulting and evaluation service in relation to superconductor cables, superconducting materials, accessories of superconductor cables, low-temperature and vacuum systems and monitoring systems, and offers a package of solutions concerning engineering application of superconductor cables to power grid operators. The core workforce of the company consists of members from Shanghai Electric Cable Research Institute's high temperature superconductor team, the only team in China that has completely controls independent intellectual property rights and technologies in relation to the design and manufacture of the superconductor cable system. 

1km-long superconductor cable demonstration project in Shanghai enters the final stage 

"It is highly difficult to expand power transmission systems in central urban area in Shanghai, the megacity that features high cost of land, and high cost of constructing pipe gallery and underground construction of aerial conductor. Low-loss and pollution-free superconductor cable with strong power transmission capacity can effectively reduce the amount of land and underground gallery required and it has become a new solution to the transformation of urban power grids." said Zhang Xize from Shanghai International Superconductor Technology Co., Ltd. 

It takes 20 years for Shanghai to drive the project from laboratory stage to commercial production. As mentioned by Zhang Xize, the superconductor experts in Shanghai considered making a breakthrough in superconductor cables by achieving technological innovations on the basis of import and absorption of foreign technologies. However, foreign superconductor leaders refused to sell core technologies or equipment and stated a whopping price for materials. Thus, they decided to break through obstruction and accomplish the important task on their own. 

Shanghai International Superconductor Data Center 

In order to turn technological ideas into reality, all participants have made great efforts. For example, the temperature difference between inside and outside of the heat-insulated pipe sleeve is over 200℃ and it is used under high voltage of over 10,000V and current of over 1,000A. In order to ensure that the superconductor cable provides stable service for urban areas in Shanghai, the problems of heat insulation, isolation, airtightness and strength of the sleeve need to be resolved, which is highly difficult. 

The sleeve outside each segment of superconductor cable is several hundred meters long and manufactured in a one-off manner. The continuous processing method of corrugated pipes is originally developed by an enterprise in Shanghai. In fact, almost all technologies and equipment required for the superconductor cable project are independently developed in Shanghai, since no enterprise in other places of China have concerned technologies in hand, and no foreign enterprise agreed to sell patents of core technologies. 

Overall, core technologies supporting the 1.2km long superconductor cable in relation to the most crucial superconducting materials, cable structure, key components and pipe-jacking construction are results of independent innovation of Shanghai. 

Thus, Shanghai is basically ready to drive superconductor cable from the laboratory stage to commercial production. 

In 2010, China's first superconductor cable with cryogenic insulation passed the prototype test. 

On November 11, 2021, Shanghai Superconductor Manufacturing Innovation Center established by Shanghai International Superconductor Technology Co., Ltd. passed the expert review organized by Shanghai Municipal Commission of Economy and Information Technology. It is the first manufacturing innovation center in Baoshan District.

In 2013, Shanghai Superconductor Technology Co., Ltd., in collaboration with Baosteel Group, built the demonstration project of 50m long 35KV HTS cable system which has stably operated for over three years. The carrying capacity and maximum instantaneous current of the cable system are among the highest in the world. Encouraged by the successful case of Baosteel Group, State Grid Shanghai Municipal Electric Power Company decided to apply superconductor technology in the major power grid in downtown area of Shanghai to facilitate the development of superconductor industry in Shanghai. 

The demonstration project of Baosteel Group has operated stably for three years. 

The superconductor cable has a structure similar to that of a tricolor ballpoint pen, which can be found only in Shanghai. 

The superconductor team acquired valuable operating data of the superconductor cable demonstration project of Baosteel Group from 2013 to 2016. The research team tested the superconductor cable against various standard environments and limits like lightning surge, thermal cycle, long-term stress of superconducting joints, and failure of cooling system on the basis of numerous experimental data collected during the pilot scale tests from 2008 to 2018. 

In 2018, the core workforce of the team established Shanghai International Superconductor Technology Co., Ltd. In 2019, the company undertook the task of constructing the Chinese 1km- long Superconductor Cable Demonstration Project (a project of strategic emerging industry in Shanghai). It was the first time that superconductor cable was installed in central urban area of a megacity in the world. 

"We are part of the system," emphasized Zhang Xize, "We have no chance to succeed without the support from the government, upstream and downstream partners, and the superconductor alliance." Shanghai International Superconductor Technology Co., Ltd. is also a provider of general integrated design of superconductor cable system. 

Baoshan District offered guidance and assistance to Shanghai International Superconductor Technology Co., Ltd. in relation to the mechanism of commercializing research results of the company, the integration of upstream and downstream industrial chains and industrial support policies through the whole process. Shanghai High-temperature Superconductor Industrial Base was also built to facilitate the development of the superconductor industry. All these efforts provided the basis for the superconductor industry to develop on a large scale. Furthermore, Baoshan District is making active efforts to attract upstream manufacturers of superconducting materials to further tap the potential of collaborative innovation in advanced technology.