Research And Design Of Low Power Dc Magnetic Field Power Supply For NSRL

The accelerator’s magnet power supply is a system for supplying various types of electromagnets for the accelerator.Adjusting the current of the magnet power supply,you can change the electromagnetic field of the magnet,thus controlling the orbit of the particle movement.In the field of accelerator technology,power technology is relatively independent of a discipline,but in order to meet the requirements of the accelerator,accelerator magnet power has its own characteristics.Generally,voltage ripple in the order of 10-2 or more,the current ripple in the order of 10-6 or more,long-term stability(24h)better than 10-4 or higher is needed.Power technology is a multi-disciplinary edge crossover technology that applies power semiconductor devices,integrated power conversion technology,modern electronic technology,and automatic control technology.With the development of technology,digital control pulse width modulation technology is gradually popular,it combines the advantages of digital control technology that is strong external interference,high degree of integration,good portability and pulse width modulation technology can enhance the power efficiency,to achieve miniaturization and lightweight power,and success in the accelerator magnetic field power.In this paper,the three DC-DC rheological changes,namely,isolated,non-isolated,resonant changes are briefly described,and in the three categories,respectively,examples of buck buck converter,flyback converter,series resonant converter Circuit working principle,voltage and current characteristics.Introduced the design of the switching power supply control loop:the basic concept of the switching loop and the example of the simple buck Buck converter simulation control loop design flow.Based on the design requirements of the accelerator for low power correction magnet power supply,this paper designs a low power DC power source with output below 2kW.This design uses pulse width modulation(PWM)combined with digital closed-loop feedback technology control scheme,full-bridge Buck buck chopper topology;current sensor sampling load output current,and converted into voltage signals,the microcontroller through the external ADC by The digital output of the voltage signal is obtained and the load output current value is converted as the feedback quantity.The error between the current output current and the set current is calculated and the historical difference is stored.The digital PI control regulator calculates the current Should be set pulse width duty cycle;by the microcontroller PWM square wave generated by the drive circuit amplified isolation drive Buck circuit switch,the output current waveform real-time tracking reference waveform to ensure high output current stability.Set the prototype and test,test the ADC drive output waveform to verify the ADC accuracy,test the four-way PWM drive waveform verification drive output normal,test the output voltage ripple and calculate the current ripple calculation and short-term current stability calculation,the results show that the full bridge Switching power supply topology to meet the needs of low-power DC magnet power supply.