China Deploys First High-Temperature Superconducting Low-Voltage DC Cable in Suzhou

Considering the massive integration of renewable energy such as wind and solar, the growth of DC loads like electric vehicles, and the emerging application of superconducting materials in the power sector, DC grids have become a new research direction.

According to CCTV, China’s first high‑temperature superconducting low‑voltage DC cable was officially put into service in Suzhou, Jiangsu, filling a domestic gap in low‑voltage DC superconducting cable applications and providing strong impetus for new‑type power system construction and energy transition.

The country has explored superconducting cable applications, but mainly in AC demonstration projects; the high‑temperature superconducting low‑voltage DC cable can reduce grid line loss by about 70% compared to AC superconducting cables.

Literature data show that AC high‑temperature superconducting cables have losses of 3%–4%, whereas DC superconducting cables have losses of only 1%–2%.

In June 2020, the Suzhou Wujiang District government, State Grid Suzhou Power Supply Company, and Jiangsu Yongding Co., Ltd. launched a demonstration project for a high‑temperature superconducting DC cable, planning a roughly 180‑meter cable in the Wujiang Tongli low‑voltage DC distribution network to connect a 10 kV DC center station with a factory’s DC distribution room.

The project uses domestically produced second‑generation YBCO high‑temperature superconducting tape, achieving domestic core material production, and adopts a coaxial positive‑negative electrode design, making it the most compact superconducting cable in China.

According to Yang Chen, deputy director of the equipment department of State Grid Suzhou Power Supply Company, the cable is designed for a voltage of ±375 V, a maximum current of 4500 A, and a conductor cross‑sectional area of 90 mm².

Compared with conventional PVC copper core cables of the same voltage level, the conventional cable’s cross‑sectional area is about twice as large, yet the superconducting cable can deliver roughly 20 times the power capacity with conductor losses only one‑tenth of those of conventional cables.