Control and Protection Strategy of Toroidal Field Magnet Power Supply System in HL-2M

The HL-2M device is a new generation tokamak at the Southwestern Institute of Physics that is used to develop nuclear fusion research. To confine the plasma, the toroidal field (TF) coil of HL-2M is needed to output 140-kA direct current to generate a 2.2-T magnetic density flux. Therefore, the TF power supply system was developed. It is powered by two flywheel pulsed motor-generator sets, and a cophase counter parallel connection bridge rectifier was used to provide more current. According to the TF power supply system topology, the amplitude of the magnetic flux density of the TF coil can be tuned by adjusting the excitation system of the flywheel pulse generator; the control strategy and mathematical formula are given. Then, the TF power supply protection system is established, and protection strategies under different faults are designed. The control and protection performance of the TF power supply system has been successfully applied and verified in the first plasma discharge of the HL-2M experiment.