Research And Design Of Isolated Bidirectional Full Bridge DC-DC Converter

With the emergence of the energy crisis and the strengthening of the awareness of environmental protection by governments all over the world,new energy technology has been rapidly developed,with the development of power electronics technology,which the emergence of isolated bidirectional full-bridge DC-DC converter,in the distributed energy storage system,electric vehicle power system,and power electronic converter has been used in practice.Isolated bidirectional full-bridge DC-DC converter topology is symmetrical,flexible control method,with electrical isolation,the use of phase transfer control,easy to achieve soft switch,high transmission efficiency,low current stress,so widely used in high-voltage high power and other occasions.On the topology of the isolated bidirectional full-bridge DC-DC converter,the two control methods of single-phase-shift control and dual-phase-shift control are compared and analyzed,and under the unified mathematical model,the mathematical relationship between transmission power and phase shift angle can be derived by analyzing the switching process,and the relationship between reflux power and phase shift angle is analyzed,and its power characteristics,Current stress conditions and soft switch range.In view of the uneliminatable characteristics of the reflux power under single-phase-shift control mode,the boundary condition of the soft switch is realized jointly under the control mode of the dual-phase-shift control,and an optimal phase shift angle is calculated,according to which the control strategy aimed at reducing the reflux power is proposed,and then the simulation model is built on the Matlab/Simulink simulation platform,and is the principle verification of the above two control methods is proved to be correct.Finally,a 100 W physical prototype platform was set up,the hardware part and the software part were designed,the two control methods were verified on the physical prototype,the experimental results and the previous analysis were basically in line with the correctness of the previous principle.