Multiple control system design for superconducting power supply based on RST algorithm

The power supply for the superconducting outsert of Steady High Magnetic Field Facility (SHMFF) in High Magnetic Field Laboratory of Chinese Academy of Sciences requires very high precision and high stability (10 ppm of 13kA). In this paper, a multiple controller has been developed which is in combination with analogue control in the voltage-loop and digital control (RST algorithm) in the current-loop. The system model and the detailed design and evaluation of the method are all presented. And the simulation and experimental results finally manifests that the output current can follow the reference perfectly (no lagging error, no overshoot), and its precision (<10ppm) and the output voltage fluctuation (<1%) both meet the requirements. Therefore, the proposed control system for the superconducting power supply is proved to be feasible.