高压大功率场合LCC谐振变换器的分析与设计

Analysis and Design of LCC Resonant Converter for High Voltage and High Power Applications

具有电容型滤波器的LCC谐振变换器十分适用于高压大功率场合,由于具有三个谐振元件,变换器在工作中呈现出多谐振的过程,使得分析与设计繁琐复杂。本文分析了其工作原理,采用基波近似法得到了该变换器的等效交流电路,在此基础上推导了它的数学模型,提出了一种详尽的设计方法,该方法简单、直观并且准确,可以保证所有开关管在全负载范围内实现零电压开关,减小电流应力、轻载环流和开关频率的变化范围。通过一台输入100V,输出16.5kV/230mA,采用变频控制的样机验证了设计的正确性。

LCC resonant converter with capacitive output filter is found out to be suitable for high voltage and high power applications. As it has three resonant elements the converter enters into multi-resonant modes which makes it difficult to analyse and design the converter. This paper demonstrates the performance of LCC resonant converter with capacitive output filter and proposes a comprehensive design procedure for it based on its steady model, aiming to achieve zero-voltage-switching （ZVS） throughout the entire load range, to reduce the current stresses, to reduce the circulating current at light load and the range of switching frequency variation. A 100V input, 16.5kV/230mA output prototype with variable frequency control strategy is built to verify the design method.