新型谐振式开关电容变换器及其潜电路分析

Novel Resonant Switched-capacitor Converter and Analysis of Its Sneak Circuit

针对传统三电平开关电容变换器存在硬开关或软开关实现较苛刻的不足,提出一种恒流充电谐振放电的新型1/2降压式开关电容变换器,谐振电容的谐振电流脉冲数减半,增大了电流占空比,降低了谐振电容的阻性损耗。以电路谐振和能量变换的规律,分析了输出电压、充电脉冲平均电流和变换效率等数学表达式,并得出一种简单的减少潜电路产生的新方法。这种谐振型开关电容变换器在一定范围内可通过调频方式调压,是一种谐振电感量小且效率高的直流变换器。最后通过仿真和实验验证了电路及其分析过程的正确性。

Aimed at the shortcoming of the traditional three-level switched-capacitor converter,i.e.,it is difficult to implement hard-switching or soft-switching,a novel half step-down switched-capacitor converter with constant current charging and resonant discharge is proposed in this paper.The number of resonant current pulses in the resonant capacitor is reduced by half,thus increasing the current duty cycle and reducing its resistive loss.According to the laws of circuit resonance and energy conversion,the mathematical expressions for output voltage,average current of charging pulse and conversion efficiency are analyzed,and a simple novel method to reduce the generation of sneak circuits is obtained.This type of resonant switched-capacitor converter can regulate the voltage by frequency modulation in a certain range,which is a DC converter with a small resonance inductance and a high efficiency.Finally,the circuit and its analysis were verified by simulation and experimental results.