一种PWM控制宽输出LLC变换器  

PWM controlled wide output LLC converter

作　　者：何圣仲[1] 陈宇航 代东雷 吴斌 何晓琼[1] 徐英雷[1] HE Sheng-zhong;CHEN Yu-hang;DAI Dong-lei;WU Bin;HE Xiao-qiong;XU Ying-lei(College of Electrical Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学电气工程学院,四川成都611756

出　　处：《电机与控制学报》2022年第6期62-71,共10页Electric Machines and Control

基　　金：国家自然科学基金(52077181);四川省科技厅资助项目(2019JDTD0003)。

摘　　要：针对传统LLC谐振变换器应用于车载充电等宽输出电压场合,其谐振参数设计困难且输出电压增益受负载影响较大的问题,提出一种基于脉冲宽度调制的宽输出LLC谐振变换器。该变换器原边为全桥结构,副边含有一个辅助MOSFET,通过控制该辅助MOSFET的占空比实现对输出电压的调节。在输出电压变化时,所有的器件均工作于谐振频率,MOSFET均实现了ZVS开通,二极管均实现了ZCS关断。与传统LLC谐振变换器相比,其具有较宽的输出电压增益范围且该增益范围与负载和谐振元件参数无关。最后,设计了一台420 W的实验样机来验证该变换器的可行性。变换器输入为130 V,输出为70~140 V,开关频率为100 kHz,峰值效率达到了96.17%。实验结果表明,PWM-LLC变换器在较宽的输出电压范围内,具有良好的性能。The traditional LLC resonant converter is applied to the scenario with the requirement of wide output voltage ranges, e.g., electric vehicle charging applications, its resonant parameters are difficult to design, and the output voltage gain is greatly affected by the load. An LLC resonant converter with wide output voltage ranges, based on pulse width modulation is proposed. The primary side of the converter is a full bridge structure, and the secondary side contains an auxiliary MOSFET.The output voltage is adjusted by controlling the duty cycle of the auxiliary MOSFET. When the output voltage changes, all devices work at the resonant frequency, all MOSFETs realize zero voltage switching and all diodes realize zero current switching. Compared with the traditional LLC resonant converter, it has a wide output voltage gain range, and the gain range is independent of the load and resonant element parameters. Finally, a 420 W experimental prototype is designed to verify the feasibility of the converter. The input of the converter is 130 V, the output is 70~140 V, and the switching frequency is 100 kHz, and the peak efficiency reaches 96.17%. The experimental results show that the PWM-LLC converter has good performance in the wide output voltage ranges.

关 键 词：PWM控制 宽输出 零电压开通 零电流关断 定频 LLC谐振变换器 

分 类 号：TM461[电气工程—电器]