Design Study on Pulsed Power Supplies for the J-PARC Main Ring Magnets Using SMES

The proton synchrotron of J-PARC provides 30 GeV of a high-intensity proton beam. In a rapid-cycling operation scenario with 1 s of the cycling period, the peak-to-peak power disturbance will be 140 MW. In order to minimize the peak power from the grid, the authors discussed the feasibility of SMES for the 30-GeV rapid-cycling operation and carried out the design study on the power converter system and the SMES coils based on the simulation results and the magnetic field analysis. In this paper, the authors propose an optimal power converter topology with SMES, which is composed of thyristor converters, the main ring (MR) magnets, and SMES linked by the dc voltage source capacitor. The required power for the rapid-cycling operation is mainly transferred between the MR magnets and SMES. The thyristor converters for the grid connection provide a constant current to the dc link in order to compensate the power losses. Using the 20-MJ class SMES, the required power from the grid can be reduced to 3.4 MW of the constant power.