A 50-T High-Stability Flat-Top Pulsed Magnetic Field Energized by a 100-MW Pulsed Alternator-Rectifier Power Supply With Model Predictive Control

High-stability flat-top pulsed magnetic field, which combines the advantages of pulsed high magnetic field and steady high magnetic field, is widely used in in the fields of physics, biology, and chemistry. The pulsed alternator-rectifier power supply, with controllable output voltage, is suitable to discharge a multicoil magnet to generate a synthetic flat-top magnetic field with high parameters. However, the coupling characteristics of coil current and the time-varying nonlinear characteristics of magnetic field system bring challenges to generate a high-stability flat-top pulsed magnetic field. This paper first adds a decoupling transformer in discharge circuit of the 50-T flat-top pulsed magnetic field system existed at the Wuhan Nation High Magnetic Field Center, Wuhan, China, and hence, the coupling effect of 50-T dual-coil magnet can be eliminated. Then, a control method of high-stability flat-top pulsed magnetic field based on the model predictive control is proposed. A prediction model of rectifier trigger angle is obtained by establishing the mathematical model of the system. A simulation model is built by MATLAB/Simulink to simulate the discharge process, and a 50-T/120-ms flat-top pulsed magnetic field with an accuracy of 400 ppm is generated.