Research Of High Stability Flat-top Pulsed Magnetic Field By A Compensation Power Supply

As an important tool for scientific experiments,high magnetic field plays an important role in many scientific researches,such as NMR experiments and Terahertz radiation sources.The development of these researches puts a high standard on the strength and stability of strong magnetic fields in turn.The flat-top pulsed high magnetic field attracts many researchers' attention for the advantages of high strength and good stability.There are many types of flat-top pulsed high magnetic field power supply system.Among them,pulsed generator-rectifier power supply is widely used in flat-top pulsed high magnetic field experiments,because the storage energy density is much higher than that of other kind of power supply and the controllability of the output waveform is better.However,in large capacity power supply system,the precise of the output waveform through the feedback excitation regulation of the pulse generator cannot satisfy the stability of magnetic field in frontier science research.This paper proposed a high frequency switch power supply to compensate the ripple of pulsed generator-rectifier power supply in parallel,according to the characteristics of pulsed generator-rectifier power supply system.The coordinate work of the compensation power supply and the pulsed generator-rectifier power supply is analyzed.The power matching model is simplified to DC and AC path model to analyze respectively.The power matching of power supply and the compensation of ripple is analyzed thoroughly.The feasibility of the theory is verified by Simulink.A small test platform is built for experimental verification of power matching.The pulsed generator-rectifier power supply is simulated by a three-phase rectifier circuit,and the compensation power supply is realized by the high frequency phase-shifted full bridge circuit,in which a soft switching technology is adopted to reduce switching losses.During experiments,the influence of parameters on the waveform is analyzed in detail,which proved the feasibility and correctness of the theory.Meanwhile,some problems are encountered and solved,such as common ground link of dual power supply and electromagnetic interference of high-frequency circuit and so on.Finally,the experiment results is summarized,the shortages and optimization are proposed.