Design of a Current-Controlled Power Supply for High-Stability Flat-Top Pulsed Magnetic Field

A flat-top pulsed magnetic field is of great interest for scientific experiments that need both high strength and high stability in the magnetic field. A battery bank with advantages of large energy storage and relative voltage stability is an ideal power supply for a flat-top pulsed field. However, due to the change of magnet resistance during discharge progress, the battery system is unable to maintain a flat-top magnetic field alone. This paper presents a current-controlled power supply based on batteries for a high-stability flat-top pulsed magnetic field at the Wuhan National High Magnetic Field Center. An active parallel circuit is proposed as an auxiliary power supply integrating the present battery system to be a current-controlled power supply, which can sustain a 35-T/270-ms flat-top pulsed field with the ripple less than 100 ppm. The prototype of the scheme has been developed, and experiments will be carried out in early 2016 on schedule. After introduction of the circuit topology and control strategy, digital simulation results are discussed in this paper.