基于LLC串联谐振的半桥变换器的研究

图 1LLC 串联谐振半桥变换器图 2LLC 串联谐振变换器等效电路在这种电路中，开关工作频率可以低于 LS、CS 的本征谐振频率 fo，而只需要高于 LS、Lm、CS 的谐振频率 fm 即可实现主开关的零电压导通。由于利用了变压器的励磁电感 Lm，其电压传输特性为：G −S − V (S) R // SLV (S)1R // SL  SL  SCS L C 1 SL / R  S C L  L  S L L C / R f − 1 / 2p L C f − 1 / 2p −L  L C 基于 LLC 串联谐振的半桥变换器的讨论门秀萍(安徽财经大学 管理科学与工程学院，安徽 蚌埠 233030)摘要：提出了一种新型 LLC 串联谐振变换器。它可使原边所有的开关管零电压导通、副边的整流管零电流关断，因而可实现极高的转换效率。由于电路利用了变压器的励磁电感，可使变换器在宽输入范围内实现软开关。此外，利用漏感参加谐振，可有效降低副边整流管的电压应力，提高 EMI 性能。在分析 LLC 串联谐振变换器工作原理的基础上，设计了实验样机。实验结果证明，变换器转换效率可达到 92.1%。关键词：软开关技术；零电压开关；LLC 串联谐振变换器中图分类号：TM 56 文献标识码：A 文章编号：1002-087 X(2024)03-0410-04Research on LLC series resonant half-bridge converterMEN Xiu-ping(School of Management Science and Engineering, Anhui University of Finance & Economics, Bengbu Anhui 233030，China)Abstract: A novel soft switching LLC series resonant converter was presented, in which all switches were working on the ZVS and the secondary diodes were working on the ZCS, so a high efficiency could be achieved. In order to realize soft-switching over the entire operating, the magnetizing inductance was utilized to widen the input range. Moreover, the leakage inductance participate in resonance could effectively reduce EMI and secondary rectifier voltage stress. Based on the detailed analysis of the principle of LLC series resonant converter, a power supply was manufactured. The result proves that the efficiency can reach 92.1%.Key words: soft-switc...