一种多模式复合调制的L-R型LCC谐振变换器

Multi-mode compound modulation L-R LCC resonant converter

提出一种多模式复合调制的线性-谐振(L-R)型LCC谐振变换器。该变换器根据Boost调制的思路,结合传统LCC谐振变换器,实现了电感电流线性-谐振型变化的转换,具有全负载范围的软开关特性。在复合调制方式下,变换器能实现3种工作模式的互相转换以适应宽输出电压和负载变化范围的应用场合,解决了传统LCC谐振变换器在轻载条件下难以实现软开关的问题。与已有的Boost调制型谐振变换器相比,所提变换器通过后置并联谐振电容,在构成LCC谐振腔的同时,配合后级LC滤波结构,解决了Boost调制模式下谐振电流断续导致输出纹波大的问题。详细描述了各模式工作原理,推导了各变量的时域表达式,得到了比较精确的电压增益关系式。最后基于恒流-恒压充电模式设计了一台输入电压为110 V、输出电压为80~150 V、输出电流为0~3.33 A、最大输出功率为500 W的实验样机,给出了各参数以及模式转换的设计方法,实验结果证明了理论分析的正确性。

A multi-mode compound modulation L-R(Linear-Resonance)LCC resonant converter is proposed.The proposed converter combines traditional LCC resonant converter with Boost modulation to realize the conversion of inductive current between linear and resonant type,and achieves the soft switching characteristic in full load range.In composite modulation mode,the converter can be converted among three operating modes to adapt to the application with wide output voltage and load range,which solves the problem that it is difficult to realize soft switching in traditional LCC resonant converter under light load.Compared with the existing Boost modulation resonant converter,the proposed converter uses a rear-mounted parallel resonant capacitor to construct the LCC resonant structure and cooperate with the back-end LC filtering structure,which solves the problem of large output ripple caused by discontinuous resonant current under Boost modulation mode.The working principle of each mode is described in detail,the time-domain expressions of each variable are derived,and the voltage gain expression with more accuracy is obtained.Finally,based on the CC-CV(Constant Current and Constant Voltage)charging mode,an experimental prototype with input voltage of 110 V,output voltage of 80~150 V,output current of 0~3.33 A and maximum output power of 500 W is designed.The design method of each parameter and mode conversion is given,and the experimental results prove the correctness of theoretical analysis.