Design Of Interleaving Bi-directional LLC Resonant Converter And Its Magnetic Integrated Component

The converter is an important link in energy transmission,improving its efficiency is a hot topic in recent years.Based on the study of the bidirectional LLC resonant converter and the staggered parallel LLC resonant converter,this paper analyzes the working characteristics,working principle and working process of the interlaced parallel bidirectional LLC resonant converter in the ideal working frequency range,and obtains the expression of the input impedance and voltage gain,in order to analyze the specific working model of the converter.The theoretical basis is provided for selecting parameters of resonance element.At the same time,in order to achieve zero voltage switching from light load to full load,two limiting conditions are proposed.A "UIU" type coupling inductor structure is proposed.By analyzing the magnetic flux distribution of the coupled inductor,the magnetic circuit model is built,and the calculation formula of self-inductance,leakage inductance and mutual inductance is obtained,and the design method of the coupled inductor is given.Through simulation and experiment,the correctness of the magnetic component model is proved.It is concluded that the "UIU" type coupling inductor has the advantages of simple processing,large inductance,more uniform distribution of magnetic flux density,high magnetic core utilization and not easy to saturate.It is applied to interleaved bidirectional LLC resonant converter,which has the advantages of simple structure and high efficiency.Then,the parameters of the resonant network are analyzed and calculated according to the working characteristics of the converter and the ZVS conditions.At the same time,a kind of "UIU" core structure transformer is designed according to the parameters,which has a higher power density compared with the traditional transformer.The feasibility of the resonant parameters and the reliability of the selected devices are verified by saber simulation.Then a prototype of 1KW is built,which achieves high transmission efficiency in the full load range,and further verifies the correctness of the theory.