【作者】 刘欣；

【导师】 隋涛；

【作者基本信息】 山东科技大学 ， 电气工程（专业学位）， 2018， 硕士

【摘要】 近年来全球汽车保有量仍呈快速上升的趋势,传统燃油汽车造成的环境污染以及不可再生能源消耗过度问题也越来越严重。随着人们的环保呼声日益强烈和发展新能源意识连年提高,新能源电动汽车应运而生。但在电动汽车推广与应用过程中仍存在缺少大量的高效率、体积小、稳定的充电模块等问题,因此开发一款高性能的充电模块对推动电动汽车产业发展具有重要意义。DC/DC变换是充电模块的核心,传统的硬开关DC/DC变换器在开关时因电压电流波形产生交叠等限制,普遍开关耗损较高。本文设计了一种基于半桥LLC谐振变换器电动汽车充电模块,半桥LLC谐振拓扑具有能够实现软开关(ZVS)的高效率传输的优点,且变压器工作于高频状态,体积小,十分适合作为电动汽车充电机的主功率模块。文中首先对半桥LLC谐振拓扑的工作原理进行分析,依照原理将半桥LLC谐振分为三种不同工作模式,并对不同模式下工作模态进行研究分析。通过基波分析法(FHA)建立了 LLC谐振电路的等效模型,得出其增益特性,并利用仿真软件MATHCAD绘制其增益特性曲线,根据增益特性曲线分析主要谐振参数电感比以及品质因数对参数取值的影响。在此基础上进行基于半桥LLC谐振的低速电动汽车充电模块主电路参数设计,并利用仿真软件PSIM验证谐振腔元件参数设计的可行性,保证其能够实现高效率传输,并简要设计前级AC/DC的Boost型APFC电路。然后针对电力电子设备的数字化发展趋势以及电动汽车动力电池的几种充电方式,设计了基于半桥LLC谐振充电模块的先恒流再恒压的分阶段双PI闭环数字PFM控制方案。并基于STM32F103C8T6数字控制芯片,设计电压电流采样电路及输入欠压保护等外围硬件电路,先通过仿真软件Saber进行闭环PI参数验证,最后制作了一款550W样机并搭建了实验平台,并对相关波形进行测试,验证了理论分析的可行性及正确性。更多还原

【Abstract】 In recent years,there is an uprising trend for vehicle holding quantity.On the other hand,the pollution problem by conventional combustion engine car is also getting more and more severe.Therefore,the Electrical vehicles(EVs)market has a rapidly growth due to the rising awareness for environment protection for the recent decade.For the further market growth and wider adoption of EVs,highly-efficient,small-volume and reliable on-board charging solutions are the key factor among any others.DC/DC converter is a core piece of an on-board charging solution.Conventional DC/DC converter with hard-switching is not suitable for EVs’application due to the high losses during the switching transient.On the other hand,a LLC resonant converter based EV charging module,with features of ZVS,high switching frequency and smaller size,is designed in this work.All these advantages make it suitable for EV applications.Firstly,operational principles of three different working modes of the circuit is analyzed in details.Secondly,LLC resonant circuit is modeled based on first harmonic approximation(FHA).Through the modeling,the gain curve is derived and plotted in MATHCAD to analyze the impact on resonant tank parameter selections by quality factor and inductance ratio.Moreover,parameter design and component selection is accomplished based on aforementioned analyses and verified through PSIM simulation.Thirdly,a brief description of front-end APFC circuit design is mentioned.Due to the increasing popularity of digital control,a dual PI loop PFM control solution for CC-CV charging profile is designed and implemented based on STM32F103C8T6 with sensing and UVLO circuitry.The control loop design is verified by Saber simulation first,and then implemented and tested on a 550W laboratory testing set-up.The effectiveness of the design is validated by experimental results.更多还原