Research And Design Of Bidirectional LLC Resonant Charging Topology Based On DSP28335

Due to the increasing shortage of the global fossil fuels and aggravated environmental pollution,the development of the new energy sources is becoming increasingly important.With the rapid development and promotion of the clean-energy electric vehicles,the corresponding high-efficient charging methods and charging devices have become the focal point of researches worldwide.In order to enable the battery to be safely and efficiently charged,this article focus on both the pulse charging method and bidirectional DC/DC charging topology.The specific process of the work is as follows:First of all,this article analyzes the working principle of lead-acid batteries and the the polarization phenomena generated during the charging process,studies the principles of quick-charging,points out the reasons why the traditional charging method makes quick-charging difficult,compare and analyze the existing quick-charging methods and depolarization,ensuring the positive and negative pulse charging method is applied in this article.By comparing the advantages and disadvantages of different types of bidirectional DC/DC charging topologies,the bidirectional full-bridge LLC resonant topology is selected as the main charging circuit.Secondly,through the detailed analysis of the principle of resonant topology of the bidirectional full-bridge LLC and its steady-state model,the article analyzes influence of the resonant parameters changes on its DC gain characteristics,therefore,working out the appropriate resonant parameters.The bidirectional LLC resonant converter is controlled by using a PFM(Pulse Frequency Modulation)method and a voltage-current double closed-loop control method.Finally,a simulation model was established in Saber simulation analysis software to perform open-loop and closed-loop simulations.The soft-switching,dynamic response characteristics and effect of charge and discharge were verified.On the basis of the above,the experiment platform was set up,and the TMS320F28335 control chips were used to control the bi-directional full-bridge LLC resonant topology.The main waveform was tested and the rationality of the design was verified.