In fusion reactor technology, the superconducting magnet system serves as a core component for confining high-temperature plasma, making the guarantee of its safe and stable operation crucial. Under various plasma discharge operation modes, such as steady-state long-pulse and high fusion power, the magnet system faces significant design and safety margin analysis challenges induced by electromagnetic, stress, irradiation, and thermal loads.

To address the difficulties of safety analysis under multi-physics field coupling, an integrated model for dynamic heat load loading and stability analysis was established to meet the demands of dynamic thermal-hydraulic analysis. A multi-heat source loading Python program was developed and integrated with the Gandalf and THEA codes, realizing the time-space coupled loading of nuclear heating, AC losses, and conduction heat. A high-precision current-sharing temperature (Tcs) solver with 10^-5 precision was implemented using scaling laws and the Newton iteration method. Furthermore, based on critical cooling channel selection, peak magnetic fields, and peak temperatures, the minimum temperature margin was precisely located with a spatial resolution of 10^-2 m and a temporal resolution of 0.1s. Additionally, NbTi scaling parameters were fitted and hydraulic parameters were successfully validated using experimental data from the EAST superconducting magnet system.

Applying this methodology to China's next-generation compact fusion reactor design, thermal-hydraulic and quench characteristics were analyzed for Toroidal Field (TF) and Poloidal Field (PF) magnets under steady-state, hybrid, and inductive operation modes. Results indicate that during the 10s flat-top period of the inductive operation mode, the minimum temperature margins for the TF and PF5 magnets are greater than 1.64K and 1.72K, respectively, satisfying the design limits. These findings provide a basis for magnet safe operation and safety valve selection, offering crucial design inputs for the cryogenic system.

Parallel analysis utilizing 7 classic current scenarios from EAST evaluated the system from the perspectives of temperature and energy margins. The analysis reveals a minimum temperature margin of over 1.42K and a minimum quench energy (MQE) of 212.2 mJ/cc. To explore higher physical parameters, the current was increased by 5% to 20% to analyze the resulting MQE. Results demonstrate that the magnet maintains a sufficient margin with a 5% to 10% current increase. Finally, quench analysis indicates that the hot spot temperature reaches 40K, and the entire conductor quenches in just 10s.