| The good environmental protection and energy saving properties have made electric vehicles a hot topic and a field for future development of international automobile industry.The various restrictions and charging experience of existing wired electric vehicles greatly affect the popularity of electric vehicles Though wired power transfer is the traditional technology,wireless power transfer technology performs better in safety,convenience,and efficiency.These advantages of the new method bring a promising future.The present study mainly focuses on the research and development of charger with a wireless power transfer system.Firstly,the paper lists the technical indicators of battery charger and the needs for communication and human interaction.The study analyzes the features of different kinds of DC/DC converter,the work processes and features of phase-shift full-bridge zero-voltage-switch pulse-width modulation convertor,and simulated the convertor.Based on the above-mentioned work,the present study makes a comprehensive development of the hardware circuit of battery charger in a wireless power transfer system.The study devises a overall frame work of the hardware circuit of the battery charger,fully assesses the components of the circuit with each function,develops a schematic diagram of each circuit,carefully evaluates the magnetic components,and identifies a method for choosing the model of each component.The actual model of each component is listed in the paper.Also,the present paper analyzes the charging characteristics of lithium battery and the charging strategies of charger,and selects relevant models.The advantages and disadvantages of common charging methods are evaluated and a five-stage charging method is invented to provide a better charging effect and to extend battery life.The charging strategy is carried out by TMS320F28335,including a charging control programme,a PWM control programme,and a CAN communication programme.The operation process of the software is also fully assessed.In addition,the paper develops a hardware circuit of human machine interface system based on ARM,assesses the components of each function,and devises schematic diagram and PCB diagram.The human machine interface system is developed and its operation process is assessed.The human machine interface system realizes the communication between human machine interface system and charger,and the communication between human interface system and PC,and the application of PC in monitoring and carrying out remote control of charger.Finally,the present study performs test and analysis of charger and human interface system,ensures that each technical indicator meets the design requirements,and demonstrates the initialization,self-test process and working interface of human machine interface system as wll as control programme of PC which accomplishes remote monitor and control that initially meets the design requirements. |
