Design Of Parallel Switching Power Supply Based On Phase-shifted Full-bridge

Along with the gradual improvement of performances of power electronic device and development of power electronic technologies,high frequency and large power have gradually become the development tendencies of SMPS(switching mode power supply).Furthermore,in order to satisfy requirements on large power supply,working stability and reliability,paralleled current technology of SMPS have been enjoying the flourishing development day by day.By focusing on practical application requirements of SMPS functioning under large power and high frequency conditions,and integrating with the soft switch technology,the article studied and designed the main circuit SMPS architecture on the basis of phase-shifted full-bridge technology,established paralleled system based on master-slave control according to the widely-applied paralleled current sharing technology,and finally accomplished the overall design of the paralleled-type SMPS.The article firstly introduced the current research status and development tendency of SMPS,and analyzed common SMPS paralleled current sharing technology,small signal modeling technology and control mode of the switching regulation system.Then the article putted forward that the average-current control switching regulation system with the master-slave current-sharing control is proposed as the realization scheme of the product designed in this subject.Then,by analyzing the working process of the phase-shifted full-bridge ZVS(Zero Voltage Switch)converter,the article designed general circuit structure of the paralleled-type SMPS and the main circuit structure of a single module,calculated circuit parameters and selected devices,used the “magnetic integration” scheme as the optimum design of the main transformer.The article analyzed methods to eliminate EMC(Electro Magnetic Compatibility)interference in the paralleled system,and putted forward “frequency interleaving” program,based on which,hardware scheme of the overall control circuit was designed,and parameters of the feedback control loop were selected and designed according to the engineering commissioning method.Finally,in order to satisfy the request of practical applications and verify feasibility and reliability of the system,the overall system was experimented and tested.According to the experiment,current sharing effects among various modules in the designed paralleled-type SMPS system are satisfactory;the whole machine has considerable transient performance and steady-state performance;it is fully capable of satisfying the request of practical applications.