부산대학교 도서관

A conceptual 20 MW high-temperature superconducting (HTS) motor (HTSM) with a novel glass-fiber reinforced plastic (GFRP) racetrack ring in the flexible support rotor was explored in this study. To support the cold mass at operating conditions, the high-strength, lowleakage GFRP racetrack ring was designed as follows. First, conceptual design of the 20 MW HTSM was conducted, and the torque transmitted by the GFRP racetrack rings was obtained through electromagnetic analysis. Second, a GFRP racetrack ring was designed, and its total cross-sectional area was obtained through theoretical analysis. Third, thermal leakage and stress were calculated and examined through theoretical and finite element analyses, respectively. The GFRP racetrack ring with the “D” ring was selected based on the results. The thickness and width of the GFRP ring were set to 16 and 10 mm, respectively, and the thickness of the “D” ring was 3 mm. Then, a full-scaled GFRP ring was fabricated, and its strength and stiffness were tested via room-temperature and low-temperature tensile tests. The average tensile strength and average Young’s modulus of the GFRP ring at room temperature were 1131.5 MPa and 49.9 GPa, respectively. The strength of the GFRP ring at 193.4 K was 1243.9 MPa, and the Young's modulus of the GFRP ring at 141.3 K was 69 GPa. Lastly, a new 200 kW HTS generator was assembled using a scaled rotor with the same structure as the 20 MW HTSM and the original stator of an existing 200 kW generator. The test system was built to evaluate the feasibility of the GFRP ring before manufacturing the 20 MW HTSM. Test results showed that the GFRP ring is feasible, the design method of the GFRP ring is credible. The GFRP ring is suitable for the cold mass support of HTSMs and other low-temperature devices.