Initiating the research of high-temperature superconducting (HTS) cables in 2003, the team completed the development of China’s first set of superconducting cable production equipment in 2007, accomplished the production of China’s first superconducting cable system and manufacturing equipment in 2010, and subsequently completed a 50-m-long, 35-kV HTS cable system demonstration project in 2013, which boasted the highest operating load in the world. In 2019, the team undertook the construction of China’s 1-km superconducting cable demonstration project, a strategic emerging industry initiative in Shanghai. This was the first time in the world that a superconducting cable was installed in the central urban area of a megacity. Covering 49,000 end users in Shanghai’s Xuhui District, the project has an annual power transmission capacity of 180 million kWh. In December 2021, the world’s first fully commercial 35-kV kilometer-level superconducting power transmission project was put into operation, creating five groundbreaking achievements: the first superconducting cable project supplying power to urban load centers, the largest transmission capacity in a commercial superconducting cable project, the longest transmission distance in a superconducting cable project, the only superconducting cable project using duct laying across the entire cable route, and the only superconducting cable project with double joints.

Over the past two decades, the team has been committed to improving the key components of superconducting cables, prolonging the life of vacuum insulated pipes, overcoming technical challenges, conducting rigorous tests in harsh environments, and mitigating various influencing factors such as lightning shocks, thermal cycling, joint wear, and refrigeration system failures. These endeavors have elevated the product quality from the laboratory level to the engineering application level, enhancing the vacuum maintenance-free life from 5 years to 10 years, reducing the leakage and outgassing rate (factory) from 10-5Pa*m ³/s to 10-7Pa*m ³/s, and improving the vacuum degree (factory) from 1-5 Pa to ≤ 0.5 Pa. With all core technologies developed domestically, the team has promulgated 1 International Electrotechnical Commission (IEC) standard, 1 national standard, 1 machinery industry standard, and 2 social organization standards in the field of superconducting cables, filling the gaps in international standards. Additionally, the team is in the process of compiling 1 energy standard and 3 enterprise standards.

As a research team engaged in cross-disciplinary collaboration, the team has continuously enhanced the manufacturing technology of superconducting cables while leveraging modern information technology to support their industrial application. Overcoming the challenge of lacking global precedents, the team has independently developed operation control systems, optimized control strategies, and established an operation and maintenance model integrating unattended functioning, remote real-time monitoring, and regular inspections. Utilizing cloud processing of digital parameters, the system enables data sharing and real-time monitoring and reduces reliance on manpower, allowing team members to comprehensively understand system dynamics and ensure the optimal operation of superconducting cables within the liquid nitrogen temperature range of minus 196 °C simply through terminal devices like mobile phones and tablets. This system has enabled the accurate collection of vast data on the electrical, mechanical, and superconducting properties of the cables. This has facilitated many pioneering achievements and led to the development of a series of standards for the production, testing, design, and construction of superconducting cables, laying a solid foundation for their widespread adoption.

Since the deployment of the superconducting cable system, it has supplied stable power to the grid for over two years, resilient against extreme weather conditions thanks to the intelligent control capabilities of the system. Notably, it has set a global record with a full-load operation of 2160.12 A for commercial superconducting power transmission lines. Comprehensive monitoring and detailed analysis by grid users have verified that the superconducting system operates normally and at an international leading level.