A hydrogen society is being promoted in Japan, and hydrogen power generation using imported liquid hydrogen is being considered [1]. The economic challenge is the cost of liquefaction [2], and effective utilization of the cold heat of liquid hydrogen is essential. We are developing a liquid hydrogen-cooled high-temperature superconducting (HTS) generator [3]. As shown in Fig. 1, liquid hydrogen is used to cool the superconducting field coil, and the evaporated gas is sent to a hydrogen gas turbine. The system can be built without a refrigerator and has almost zero cooling cost. The New Energy and Industrial Technology Development Organization (NEDO) Leading Research Program (FY2022-2024) was launched, and we have developed a 10 kW /1800 rpm HTS power generation demonstrator. A cross-sectional view of the demonstrator is shown in Fig. 2. Only the field coils were superconducting. Four 300-turn racetrack-type double pancake coils were arranged to form a four-pole rotor and were cooled using liquid hydrogen. The assembly of the demonstrator has been completed and the shipping test results will be reported at the meeting.

[1] Y. Kanehana, 2nd Hydrogen Energy Ministerial Meeting (2019). [2] DOE Hydrogen and Fuel Cells Program Record, No. 19001 (2019). [3] M. Ohya et al., IEEE Trans. Appl. Supercond., 10.1109/TASC.2024.3354697 (2024).

This presentation is based on results obtained from a project, JPNP14004, subsidized by the New Energy and Industrial Technology Development Organization (NEDO).

Keywords: Generator, High-temperature superconductor, Liquid hydrogen