摘要
传统的桥式LLC谐振变换器不适合宽电压范围输入,且其输入电流断续。为此提出了一种新型的Boost型LLC谐振变换器。通过集成两个交错并联的Boost电感,不仅可以拓宽LLC变换器的增益范围,而且可以显著减小输入电流的纹波,因此该变换器适合用在光伏、燃料电池等可再生能源发电系统中。与传统的脉冲频率调制控制相比,该变换器采用定频脉冲宽度调制控制,励磁电感和Boost电感对变换器的增益特性影响很小,可以简化谐振参数的设计,同时定频控制也有利于磁性元器件和滤波电路的设计。首先介绍了该变换器的工作原理;然后通过时域分析,对该变换器的增益特性进行了深入研究;之后对变换器的ZVS软开关条件进行了详细的分析;最后建立了一台120~240 V输入、24 V/25 A输出的实验样机,实验结果验证了变换器的实用性及理论分析的正确性。
The conventional full/half-bridge LLC resonant converter is not suitable for wide input voltage range and its input current is discontinuous. Therefore, a novel Boost-integrated LLC resonant converter is proposed in this paper. Not only is the gain range extended, but also the input current ripple is significantly minimized by integrating two interleaved Boost inductors. Thus, the proposed converter is a good candidate for renewable energy generation systems, such as photovoltaic, fuel cell and so on. Instead of conventional pulse frequency modulation （PFM）, the fixed frequency pulse width modulation （PWM） control is adopted, facilitating the optimization of magnetic components and filter circuits. Besides, it turns out that the magnetizing inductance and the Boost inductors have little impact on the gain characteristics of the proposed converter with PWM control, which is favorable for the design of resonant parameters. The operation principle is introduced and then the gain characteristics of the proposed converter are investigated in depth with time-domain analysis. Afterwards, the zero voltage switching （ZVS） conditions for all power switches are analyzed in detail. Finally, the feasibility of the proposed topology and the correctness of theoretical analysis are verified by experimental results of a prototype converter with 120-240 V input and 24 V/25 A output.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2015年第15期3895-3903,共9页
Proceedings of the CSEE
基金
国家自然科学基金项目(51077112)
河北省自然科学基金项目(E2012203163)~~
