Research On The Realization Of LLC Resonant Bidirectional Full-bridge DC-DC Converter

The development of electric vehicles in China is fast,and people have more requirements for electric vehicles.Regarding the charging and discharging of electric vehicles,a charging and discharging device capable of bidirectional energy flow is required,which has led to a bidirectional power flow of charging and discharging power devices widely used in new energy vehicles and elsewhere.In terms of DC modules in bi-directional charge and discharge devices,this paper uses a full-bridge structure and a resonant structure to combine bi-directional charge and discharge devices for research.Firstly,the working state of the two-way charge and discharge device is analyzed.In terms of the circuit steady state model,mathematical expressions are derived,and the expression of the state quantity of the circuit steady state is calculated.The change of the resonance parameters to the DC gain of the power supply is further discussed influences.Secondly,the parameters of the LLC resonant bidirectional full-bridge DC-DC converter are designed and tested in detail.Then,based on saber,the open-loop and closed-loop simulations of the LLC resonant bidirectional full-bridge DC-DC converter are performed.By controlling the turn-on sequence of the switching tubes,the LLC resonant bidirectional full-bridge DC-DC converter can be realized.By controlling the switching tube,a bidirectional charge-discharge device with a combination of a full bridge structure and a resonant structure can be realized.The simulation analysis of the saber software has verified the bidirectional energy flow.Finally,based on the previous analysis,in the actual resonant converter design,a hardware circuit design based on an analog circuit to control the switch driver chip is proposed to control the bidirectional flow of converter energy,and an LLC resonant bidirectional full-bridge DC-DC converter schematic is given.