SHGJ Superconducting Technology Corporation is currently the only superconducting cable system design and manufacturing team with independent intellectual property rights in China.
SHGJ has built the world's first kilometer-level high-temperature superconducting cable demonstration line that supports the backbone power grid of a megacity. The high-temperature superconducting cable connects two 220kV substations with a total length of about 1.2 kilometers. This line is completely independently developed, manufactured, laid and verified by SHGJ R&D team personnel.
According to the conductor structure, high-temperature superconducting cables are divided into single-phase cables, three-phase coaxial cables, and three-phase turnkey cables. SHGJ`s CTO Zhang Xize told Hay Think that a superconducting cable is a power facility that uses non-blocking superconducting materials as conductors and can transmit large currents. It has the advantages of low loss, large capacity, small size, and no pollution. Under the design voltage of 35 kV, a superconducting cable can carry a large current of more than 2000 amperes, which is worth 4-6 traditional 35 kV large cross-section conventional cables. Due to the small size of the superconducting cable, the excavation and laying work is small, and there is no need to build a separate tunnel. It can save a lot of floor space and space for the transmission system, save valuable land resources, and greatly reduce the transmission system in the transmission system. The loss in the process saves overall investment and reduces carbon emissions.
The structure of the three-phase turnkey cable: the outer casing is wrapped with three superconducting cables that are insulated from each other. According to the conductor structure, high-temperature superconducting cables are divided into single-phase cables, three-phase coaxial cables, and three-phase turnkey cables. According to technical personnel, since this type of superconducting material needs to exhibit superconducting characteristics at around -196°C, the inside of the cable will be filled with liquid nitrogen during operation to cool the cable.
As a leading superconducting material R&D and production company in China, SHGJ is currently the only superconducting cable system design and manufacturing team in China with independent intellectual property rights. In 2005, it completed the development of China’s first set of superconducting cable production equipment and completed its independent development in 2008. China's first set of superconducting cable systems and related equipment, starting from 2018, undertook the construction of the SH city strategic emerging industry project "localized kilometer-level superconducting cable demonstration project". This will also be the world's first "kilometer-level" superconducting cable used in megacities. The demonstration line is connected by three 400-meter-long superconducting cables.