Numerical Investigation of Mechanical Characteristics of Racetrack REBCO HTS Magnet for MW-Class Wind Turbine Generator

Racetrack high-temperature superconducting (HTS) magnets can achieve high magnetic fields (>5 Tesla), and are therefore considered to be an optimal solution to replace the permanent magnets of traditional motors in wind turbine generators. Higher magnetic fields mean higher excitation currents, which can lead to the generation of GPa-level electromagnetic stress in the HTS magnets, potentially causing structural damage or quenching during its operation. In this study, a compact HTS magnet whose surface magnetic field is larger than 5 Tesla for MW-class wind turbine generator was designed. Using electromagnetic and structural combined analysis, we reproduced the behavior of electro-magnetic stress and confirmed the stress concentration and the deformation of the winding in the 5 Tesla magnet. Based on the analysis results, we also designed a reinforcing structure for the suppression of electromagnetic stress using carbon fiber material. Finally, we confirmed effectiveness of carbon fiber reinforcing structure for the stress and deformation suppression for the racetrack HTS magnet.