Research of Active Regulation for High-Stability Flat-Top Pulsed High Magnetic Field
With large energy storage and flexible control capabilities, pulse generator is an ideal power supply for flat-top magnetic fields. However, characteristics of the pulse generator, such as nonlinearity and time variance, are a limitation on improving flat-top stability. Based on the pulse generator power supply for the flat-top magnetic field at Wuhan National High Magnetic Field Center, this paper proposes an active regulator for the flat-top magnetic field. An optimal control strategy combining selective PI control and repetitive control is proposed to restrain the circulating current between the pulse generator and the active regulator. A 50 T/140 ms flat-top magnetic field with the ripple less than 100 ppm is achieved by applying an active regulator. In order to validate the effectiveness of the optimal control strategy for the high stability flat-top magnetic field with an active regulator, experimental data about the triggering angle of the rectifier are utilized in the simulation model; the result indicates that the circulating current between the pulse generator and the active regulator is suppressed to a great extent.