Design Of High Efficiency AC/DC Switching Mode Power Supply With Medium Power

In recent years,with the application of switching mode power supply in more fields,how to obtain better AC/DC conversion technology has become a key factor.In the case of higher switching frequency,how to reduce the loss and improve efficiency while reducing the pollution to the power grid is an important factor to measure the quality of the converter.In this thesis,based on the design requirements and application requirements,the system architecture of high-performance switching mode power supply is established,including two sub-modules of AC/DC converter and DC/DC converter,as well as the auxiliary power module.AC/DC converter includes PFC,filtering and control,and DC/DC converter module includes resonance,output filtering,control and protection.The improved bridge-free PFC circuit structure is used to reduce the common mode interference of basic bridge-free PFC circuit.Specific parameters of converter main circuit calculation and optimization,then the key circuit design,AC/DC converter includes auxiliary power supply,hardware and control circuit module,simulation model of AC/DC converter,the simulation results show that the largest PF rate of 99.56%,has realized the relatively perfect follow input voltage and current,meet the requirements of the system design.Level to the DC/DC converter main circuit USES half-bridge LLC resonant circuit structure,and based on frequency domain analysis method to the equivalent mathematical model was established,its circuit structure and K were analyzed in detail,fn and Q effect on the relationship between the three parameters,and the sufficient condition of ZVS realization switch tube was deduced,on the basis of design flow chart of the main converter circuit design and specific parameters of converter main circuit calculation and optimization,solved the difficult resonant circuit analysis and parameter calculation complex problems;The key circuits of the DC/DC converter are designed,including auxiliary power supply,hardware and control circuit module.The simulation model of the DC/DC converter is established.Software and hardware circuits are designed for the system,and A simulation model is established for the whole system by using PSIM software.The joint simulation results show that the output voltage is 24.04 v,the output current is 10.01 a,and the output ripple is less than 3%.The efficiency of the whole system reaches 86.49%,and the efficiency of each sub-module is more than 90%,reaching the system design index.This type of power supply is mainly used in the field of industrial power supply to provide reference for practical engineering applications and to reduce the workload and work load to a certain extent.