Magnet power supply with power fluctuation compensating function using SMES for high intensity synchrotron

The power supply for high intensity synchrotron magnet draws large amount of power from utility network. The JHF 50-GeV main ring will require 104 MW of total active power and 28.8 MW of dissipation power by estimation. Moreover, the charging and discharging cycle is repeated with 3.64 s of the cycle time at the initial operation, and the repeating frequency will be raised up by twice in future. Taking this situation into consideration, energy storage system using adjustable speed type flywheel and IGBT power converter are studied in the JHF project. In this paper, the power supply using SMES is proposed. The power supply can absorb the fluctuation of active and reactive power caused by charging and discharging the synchrotron magnet. The system is composed of current source ac/dc converter, chopper circuits and superconducting magnets. The chopper circuits for superconducting magnets and synchrotron magnets can be connected to the same dc bus of the power supply and this feature can reduce the power rating of ac/dc converters.