Research On DC/DC Converter With Dual Active Bridges In Vehicle

In recent years,the state has reduced the pollution of automobile exhaust to the environment by restricting traditional fuel vehicles and vigorously promoting new energy vehicles.In the process of transition from traditional fuel vehicles to new energy vehicles,the dual active bridge DC/DC converters used in automobile charging technology have gradually extended into an important research for electric vehicles due to their high efficiency,small power consumption,and high power.direction.In order to further improve the energy utilization rate of automotive batteries and cater to the growing vehicle DC/DC converter market year by year,this topic uses NXP’s MPC5643 L as a control chip,and uses a phase-shifted full-bridge soft switching circuit as a vehicle dual active bridge DC/DC The main topology of the DC converter is to design a switching power supply with an output voltage of 28 V,an output current of 100 A,and a rated power of up to 2.8k W.First,the working process of the dual active bridge DC/DC converter is introduced in detail.For the step-down process,six important working steps for implementing soft switching are analyzed,and the conditions for soft switching are calculated.At the theoretical level,the overall power consumption of the controller is reduced to the greatest extent,and the working reliability of the converter is improved.,Elaborated on the timing of the boost in detail,and conducted a theoretical study to realize the bidirectional energy transfer between the two power supplies.Then,from the perspective of meeting actual needs,develop a reliable hardware main circuit,control circuit and drive circuit.Through parameter calculation and model simulation of the transformer,an electrically isolated high-performance core device is designed to achieve the isolation of the high-voltage side circuit from the low-voltage side circuit,the analog circuit and the digital circuit;on the basis of hardware isolation,calculate and design the resonance network To achieve high-efficiency and high-reliability soft-switch modulation;accurately calculate and online debug all important parameters of the hardware circuit,and carry out small-signal modeling and analysis of the overall topology to achieve a wide range of work for automotive DC/DC converters.Finally,on the basis of circuit hardware design and stability analysis,the system is modeled and simulated,and the reliability of the system is verified through experiments to provide a theoretical reference for actual bench experiments.Build a DC/DC converter experimental platform,obtain system parameter data and test waveforms,and analyze the experimental results to verify the feasibility of a wide-range input,bidirectional isolation,and low-voltage high-current output automotive DC/DC converter.