Design Of AC/DC300W Digital Power Supply Based On DSP Control

Nowadays,with the rapid development of electronic science and technology.more and more electrical equipment appears and applies to people’s life.And each complete electrical equipment usually needs the power plate to drive and improve.Compared with the previous single complex analog power supply,it is the digital power supply which is used by the engineers because of its high efficiency and convenience.At the same time with the wide application of DSP has promoted the development of digital power supply.Therefore,It is urgent to study the design of digital power supply.In this paper,DSP is used as the core control processor of digital power supply,The dc output voltage is adjustable and the system achieves maximum conversion efficiency.This digital power system is composed of PFC power correction DC transform circuit DSP control circuit and auxiliary power module.On the basis of analyzing the basic principle of PFC circuit,the Boost topology of single channel is selected.The calculation and selection of components in the main circuit are completed by means of average current control.The current voltage double closed loop control and software algorithm are adopted to establish the mathematical model,and finally the design of PFC power correction circuit is completed.According to the parameter design indexes and requirements of the project,choose dual switch forward as DC transform circuit primary topology at the currently used in several classical topologies.For the drive isolation circuit,the selection and design of the positive and negative excitation transformer and the selection of the optocoupler are specially designed.DSP as the main control chip of the control circuit ts internal powerful module conversion function and time manager function,the voltage current in the circuit is sampled by program algorithm,The output PWM waveform is used to adjust the duty ratio of the power switch tube in the main circuit to control the output voltage..Finally,the main modules of the digital power supply prototype are welded and tested based on the circuit schematic diagram.The two output voltages are 18V/10A and 9V/5A,the maximum power can be achieved to 300W.All parameter indexes meet the design requirements.