Impact analysis of power supply fault-state on magnets in fusion devices

The magnet power supply system is one of the important subsystems of nuclear fusion devices. Although it has undergone strict safety and stability verification before design and operation, the experimental conditions at the work site still have uncertainty. The fast discharge unit may not be able to open and the magnet power supply may have a ground fault. Therefore, it is necessary to systematically analyze the above possible fault conditions, in order to better protect the superconducting magnet. In this paper, the quench protection system and grounding protection system of TF coil magnet power supply are theoretically analyzed and calculated. According to the calculation results, the TF coil fault simulation model is built in MATLAB/Simulink, and the influence of the fault state of the power supply on the magnet is systematically analyzed. The results show that the maximum voltage at fault is much higher than the rated voltage during operation, so a larger margin should be considered in the design process to protect the superconducting magnet. The research in this paper has certain guiding significance for the design of fast discharge unit and TF magnet coil grounding system, and plays an important role in the performance and safety of fusion device operation.