Research On Eie Integration Magnetic Component Of Staggered Parallel Bidirectional LLC Resonant Converter

Staggered parallel bidirectional LLC resonant converter is working,the circuit topology contains two transformers,six inductance,use too much magnetic parts can reduce the power density and efficiency of converter,in order to solve this problem,this paper mainly by the magnetic components of converter as the research object,respectively,the circuit topology of the transformer and the resonant inductor magnetic integration.Firstly,the operating characteristics of bidirectional LLC resonant converter in different frequency range and the input impedance characteristics of resonant network are analyzed,and the operating frequency range of the converter is determined.The expressions of input impedance and voltage gain are obtained by analyzing the ac equivalent circuit of the converter.The working process of staggered parallel bidirectional LLC resonant converter is analyzed.In this paper,the AP method is used to design the transformer parameters in the converter,including the selection of magnetic core model,winding turns,conductor shares and other related parameters.The calculation formula of transformer air gap is derived by using the energy storage formula of transformer windings.Maxwell 3D simulation software was used to analyze the transformer design and verify the rationality of the design method.An integrated transformer with EIE type magnetic core structure is proposed.The magnetic flux density of I core before and after magnetic integration was compared and analyzed to verify the advantages of decoupling magnetic integration transformer.Two resonant inductors in bidirectional LLC resonant converter are composed of transformer leakage inductors in series and external inductors.It is proposed to use EI type magnetic core to integrate the external inductors with the same parameters in the two phase converter and design two coupling inductors.Saber simulation software is used to verify that the coupling inductance can make the two phase current balance,and the coupling coefficient with the best effect of inductance current sharing is selected through simulation analysis.Since the two coupling inductors use the same magnetic core model,it is proposed to use EIE type magnetic core structure to further decouple and integrate the two EI type coupling inductors to reduce the use of I magnetic core.By comparing and analyzing the flux density distribution of I core,the advantages of EIE type integrated inductance are verified.Finally,Saber simulation software is used to verify the rationality of the parameter design of staggered parallel bidirectional LLC resonant converter.The correctness of the theory is verified by experiments.There are 58 figures,4 tables and 52 references in this thesis.