一种基于模块间移相的三相半桥LLC变换器均流控制策略  

A Current Balance Method Based on Phase-Shift Control Between Modules in Three-Phase Half-Bridge LLC Converter

作　　者：石林[1] 刘邦银[1] 段善旭[1] Shi Lin;Liu Bangyin;Duan Shanxu(State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology,Wuhan 430074 China)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学电气与电子工程学院)

出　　处：《电工技术学报》2019年第21期4551-4558,共8页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划（2018YFB0106300）;国家自然科学基金（51777084）资助项目

摘　　要：在多个LLC模块并联的系统中,各个模块之间常因参数的偏差存在电流均衡的问题。该文针对三相半桥型LLC变换器提出了一种电流均衡控制策略。所提策略基于交错并联控制下模块间移相的调制方式和三相半桥结构公共点(中点)悬浮的硬件结构,通过调节悬浮中点电压的幅值和相位以实现三相电流的均衡。首先分析了模块间移相调制方式对中点电压的影响;其次给出能够实现三相电流平衡的控制策略,主要分析了加入平衡控制环路后控制结果如何转化为实际的驱动信号移相角。实验验证了所提出方法的正确性与有效性。The multi-phase LLC converter has the problem of unbalanced phase current due to the tolerance of resonant parameters of each phase.A current balance control strategy is proposed for three-phase half-bridge LLC converter.Based on the method of phase shift modulation between modules and the structure of three phase midpoint floating LLC converter,the proposed strategy can regulate the amplitude and phase of the midpoint voltage to realize three-phase current sharing.The influence of phase shift angle between modules to the midpoint voltage is analyzed and the control strategy for three-phase current sharing is proposed accordingly.The relationship between the current balance control loop and the actual phase shift angle is derived.The experimental results verify the correctness and effectiveness of the proposed strategy.

关 键 词：三相LLC变换器 电流平衡 交错并联 移相控制 

分 类 号：TM46[电气工程—电器]