LLC谐振变换器的改进型电流解析方法  

An Improved Current Analytical Method for LLC Resonant Converter

作　　者：焦健 郭希铮[1] 游小杰[1] 王剑[1] Jiao Jian;Guo Xizheng;You Xiaojie;Wang Jian(School of Electrical Engineering Beijing Jiaotong University,Beijing 100044 China)

机构地区：[1]北京交通大学电气工程学院,北京100044

出　　处：《电工技术学报》2021年第23期5002-5013,共12页Transactions of China Electrotechnical Society

基　　金：中央高校基本科研业务费专项资金资助项目(2019-JBM062)。

摘　　要：在LLC谐振变换器中,对谐振电流的精确解析可以实现变换器的损耗计算。该文基于谐振电流近似拟合法提出一种改进型LLC谐振变换器电流解析方法,分析死区时间内的开关管结电容充放电过程、谐振电流的变化过程,通过对表达式中初始值的计算方法进行修正,该方法计算得到的谐振电流在死区时间内的变化情况更加准确。仿真结果表明,所提出的改进解析式相比原有的方法,在死区时间范围内可以准确描述谐振电流变化过程,相较于其他方法获得的初始值和励磁电流峰值,所提出方法的计算结果误差更小。实验结果进一步证明该文所提出的谐振电流解析方法的有效性和正确性。In LLC resonant converter,the accurate analysis of the resonant current can realize the loss calculation of the converter.Based on the existing approximate fitting methods,an improved current analytical method for LLC resonant converter is proposed in this paper.The charging and discharging processes of the output junction capacitor of switching devices in the dead-time are detailed analyzed.Then the changes of the resonant current in the dead-time are analyzed.Moreover,the calculation method of initial values in the improved resonant current analytical expression is modified correspondingly.The resonant current calculated by the proposed method can describe the changes of the resonant current in the dead-time more accurately.The simulation results show that compared with previous methods,the resonant current calculated by the proposed method is more accurate in the dead-time.In addition,comparing the initial values and the peak values of the magnetizing current obtained by other methods,the error of the proposed method is smaller.The experimental results further prove the effectiveness and correctness of the proposed analytical method of the resonant current.

关 键 词：LLC谐振变换器 谐振电流 改进解析法 死区时间 初始值计算 

分 类 号：TM46[电气工程—电器]