基于LLC串联谐振的半桥变换器的研究

Research on LLC series resonant half-bridge converter

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,利用漏感参与谐振,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%。

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%.