PDF《考虑寄生电容的半桥 LLC 谐振变换器参数 优化设计》

第2期现代电源技术对变换器电压输入范围和开关 频率等有较高要求.

LLC 谐振变换器能够在宽负载 范围内实现一次侧开关管的零电压开通和二次侧 整流二极管的零电流关断,具有频率高、损耗小、大 功率密度等特点,受到广泛关注[1鄄3] . LLC 谐振变换器的研究重点,主要集中在对变 换器参数的设计和优化. 文献[4]分析谐振网孔电流 时忽略了死区时间内谐振电感电流等于励磁电感 电流;

文献[5]设计变换器参数时,以谐振网孔电流 最小值为限定条件,达到降低损耗的目的,但并没 有考虑变压器寄生电容对变换器的影响;

文献[6]使 用基波分析法推导出谐振电感电流有效值公式,只 是在谐振频率点对变换器进行分析. 本文在现有研究成果的基础上,对LLC 谐振变 DOI:10.13234/j.issn.2095鄄2805.2019.2.57 中图分类号:TM46 文献标志码:A 考虑寄生电容的半桥 LLC 谐振变换器参数 优化设计 杨玉岗,孙彬彬,闫孝 (辽宁工程技术大学电气与控制工程学院,葫芦岛 125105) 摘要:含变压器的隔离型变换器易受到寄生电容的影响,降低系统运行的稳定性. 针对 LLC 谐振变换器, 建立含变压器寄生参数的等效电路模型,推导电压增益公式. 对比无寄生参数和含寄生参数的电压增益曲线, 分析寄生电容对选取电感比及其品质因数所产生的影响. 在设计参数时考虑寄生电容的影响,分析开关管实现 ZVS 的条件,推导电感比的计算方法以及品质因数的取值范围. 优化设计电感比、品质因数,进而优化各谐振参 数. 搭建实验样机,验证该优化方法的正确性和可行性. 关键词:LLC 谐振变换器;

寄生电容;

ZVS;

优化设计 Optimal Design of Half鄄bridge LLC Resonant Converter Considering Parasitic Capacitance YANG Yugang, SUN Binbin, YAN Xiaoheng (Faculty of Electrical and Control Engineering, Liaoning Technical University, Huludao 125105, China) Abstract: An isolation鄄type converter with a transformer is prone to be affected by parasitic capacitance, thus reducing the stability of system operation. In this paper, an equivalent circuit model containing transformer parasitic parameters is set up for an LLC resonant converter, and the formula for voltage gain is derived. From the comparison of voltage gain curve with and without parasitic parameters, the influence of parasitic inductance on the selection of inductance ratio and quality factor is analyzed. The effect of parasitic capacitance is considered in the design of parameters, the condition of realizing ZVS for a switching tube is analyzed, and the calculation method for inductance ratio and the range of quality factor are derived. The inductance ratio and quality factor are optimized, thus optimizing various resonance parameters. An experimental prototype was set up, which verified the correctness and feasibility of the optimization method. Keywords: LLC resonant converter;

parasitic capacitance;

ZVS;

optimal design 收稿日期:2017鄄02鄄24;

修回日期:2018鄄08鄄24 基金项目:国家自然科学基金资助项目(U1510128);

辽宁省 教育厅重点实验室基础研究资助项目(LZ2015045);

辽宁工 程技术大学第六批生产技术问题创新研究基金资助项目(20160070T) Project Supported by National Natural Science Foundation of China(U1510128);

Fundamental Research Program of Liaoning Province Education Department Key Lab(LZ2015045);

the Six鄄th Batch of Production Technology Innovation Research Foun鄄dation of Liaoning Technical University(20160070T) 电源学报Journal of Power Supply Vol.17 No.2 Mar.