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Description
Second generation (2G) high-temperature superconducting (HTS) maglev is a significant application in the field of high-temperature superconductors. As the core component of the system, the stable operation of the HTS magnet system at the target operation temperature and its ability to sustain sufficiently long offline time are of critical importance. In this work, four no-insulation (NI) closed-loop coils were wound using REBCO tapes, and excitation tests were first carried out at 77 K. After the tests were completed, a 2G HTS magnet system operating at 30 K was constructed using these coils as the core components. The system achieves cryogenic passive operation through a push-pull cryocooler design, and enables the REBCO coils to operate in persistent current mode via a detachable current source and a persistent current switch (PCS). During the experiment, the entire magnet was first cooled down, and once the overall temperature dropped to around 30 K, the magnet was energized to 48 kAt. After excitation, the power supply was disconnected. The temperature variations at multiple locations of the magnet during the excitation process were measured, as well as the magnetic field decay behavior under electrically passive conditions. Finally, corresponding simulation models were constructed and compared with the recorded experimental data. This paper summarizes the preliminary test results of the HTS magnet system, laying the foundation for its future in-orbit operation.
Keywords: high-temperature superconducting magnet, superconducting maglev, non-insulation coil, persistent current mode