Design And Implementation Of Serialized Digital Power Supply

Aiming at the miniaturization,intelligence,and multiple output requirements of modern electronic equipment,this paper designs a 480 W small Digital Power Supply,which has soft start,overvoltage and overcurrent protection and Multi-Voltage Output functions.The power supply adopted the TMS320F28069 Digital Signal Processor(DSP)produced by TI as the controller.The power supply circuit includes EMI filter circuit,Power Factor Correction(PFC)circuit,DC-DC circuit,controller circuit,sampling circuit,drive circuit,and power supply circuit.This paper has analyzed the principle of PFC and uses active PFC correction technology to design the power supply front stage to improve the power factor of the circuit.This paper has analyzed the topological structure and working principle of flyback,forward,half-bridge,DC-DC circuit chooses Half-Bridge LLC topology.This paper has accomplished parameter calculation and the component selection includes power devices such as transformers,switch tubes,rectifier diodes,etc.This paper has accomplished working modal analysis and First Harmonic Approximation(FHA)modeling and has analyzed the influence relationship between circuit operating frequency and resonance frequency,has simulated the model on the Matlab/Simulink platform.This paper has used hybrid control mode of Pulse Frequency Modulation(PFM)and Pulse Width Modulation(PWM)to achieve Multi-Voltage Output.This paper has designed the system software control program and has achieved stabilization of output voltage and current through PI(Proportion Integration)Control.According to parameter calculation and simulation results,this paper has made a power supply prototype.Test each module of the prototype,the power factor of the PFC module is greater than 0.97,the output voltage of the power supply circuit module is 12.6V,and the ripple voltage is 136 m V.DC-DC circuit prototype can output different series of voltages such as DC 48 V,36V,24 V,12V,5V,etc.When prototype outputs 48 V and 10 A,full load efficiency reaches91.08%,load regulation rate is 2.1%,voltage ripple is 0.8V.