Research On Three-phase Interleaved Magnetic Integrated Y-Y LLC Resonant Converter

In the multi-phase LLC resonant converter,the use of integrated technology can reduce the number of magnetic parts and increase the converter power density accordingly.This design takes the three-phase Y-Y type interleaved LLC resonant converter as the main research object,and carries out the magnetic integration of the three-phase transformer,the parameters of the resonant converter and the software and hardware design of the circuit topology.First,based on the topological structure of the three-phase YY type interleaved LLC resonant converter,the working principle and working process are analyzed,the fundamental wave equivalent model of the resonant network is established,the DC characteristics are analyzed,the AC voltage gain and DC voltage gain formulas are introduced,and the parameters are analyzed.Impact on three-phase resonant converters.Then,aiming at the problem of transformer magnetic integration in the three-phase YY-type interleaved LLC resonant converter,a new type of "Y" core structure transformer is proposed based on the principle of transformer magnetic integration.The structure of the transformer is analyzed and combined with the basics of magnetic integration Circuit model,the magnetic circuit model of the transformer is established,the loss calculation is carried out,and the parameter design method of the transformer is given.The "Y" type magnetic core model was built using MAXWELL simulation software,and the simulation analysis of magnetic flux density and magnetic flux distribution was realized.The magnetic flux distribution of "Y" type integrated magnetic transformer was more uniform.Bypass magnetic flux and diffuse magnetic flux were smaller.The feasibility of the theoretical design is verified.Through calculation and analysis,compared with the traditional three-phase discrete transformer,the "Y" magnetic integrated transformer has a volume reduction of more than 35%,and improves the efficiency and power density of the three-phase resonant converter.Finally,the parameter design process of the three-phase Y-Y resonant topology circuit is given,the corresponding circuit structure model is built in the PSIM software,the circuit topology parameters are simulated and debugged,and the accuracy of the design is verified through the simulation waveforms given.And according to the specific voltage,current stress and other design requirements,the appropriate main control CPU,isolation,drive and auxiliary power chip are selected to design the peripheral circuit.Using Altium Designer software to make a PCB experiment circuit board,so that the overall system can be better integrated,reduce the overall volume of the system,and improve the experimental performance of the topology circuit.An experimental prototype with an output power of 600 W and a voltage of 400V/48 V was built to effectively verify the feasibility of the new magnetic core structure and the effectiveness of the parameter design of the resonant converter.The paper has 59 pictures,2 tables,and 55 references.