Testing Results for the Cable Core of a 360 m/10 kA HTS DC Power Cable Used in the Electrolytic Aluminum Industry

IEE has installed a 360-m-long high-temperature superconducting (HTS) dc power cable at the self-supply power plant of Zhongfu Industrial Co., Ltd. in Gongyi, Henan. The cable connects a 19.5 MVA/1.5 kA silicon-controlled rectifier, which connects with a 110 kV/1 kV transformer, to the bus bar of an electrolytic aluminum cell. It is designed to carry 10 kA current and the voltage is 1300 V. The HTS dc power cable core consists of five conductor layers wound with the spliced Bi-2223 wires with the length of 40 km. The cable core has five layers and 23 HTS wires in each layer with the outer diameter of 45 mm. As the items in this project, testing of 4 to 5 m length prototype cables, including a 5 m prototype cable fabricated before the 360 m power cable and a 4 m prototype cable intercepted from the 360 m HTS power cable, is conducted. These prototypes are used to assess the design program, fabrication process, and performance of the 360 m/10 kA HTS power cable including steady state operation at the 10 kA design current and overcurrent fault capability. The critical current of the 5 and 4 m HTS power cable reach 14.3 kA and 13.8 kA at 77 K, 1 μV/cm, respectively. In this paper, the design parameters and fabrication of the 360 m/10 kA HTS dc power cable conducted by IEE are presented. The cable system, installation process and the summary of the results from the testing of 4 and 5 m prototype cables are described. In addition, details of the initial cool-down process and energizing are presented.