一类零电流谐振开关电容变换器的特性分析

具有零电流开关特性的谐振开关电容变换器是开关电容变换器的一种新拓扑形式.本文着重分析电路寄生参数和变换器运行条件对该类谐振开关电容变换器稳态特性的影响,推出变换器输出电压和效率的数学表达式,为研究负载或输入电压变化时变换器的输出性能提供了分析和设计依据.基于输出电压表达式,还提出谐振开关电容变换器的频率控制方案.全文以一个降压式谐振开关电容变换器为例详细说明公式的推导过程,并将此稳态特性分析推广到其它类型的谐振开关电容变换器.最后,文中设计了一台12V/5V/2.5A降压式谐振开关电容变换器样机,实验结果验证了本文的理论分析结果.

Characteristic Analysis of ZCS Resonant Switched Capacitor DC-DC Converters

The resonant switched capacitor(RSC) converter with zero-current switching(ZCS) is a new topology of switched capacitor converter.This paper studied the influence of circuit parasitic parameters and operating conditions on the RSC converter steady-state characteristic.The mathematical expressions of the average output voltage and efficiency were derived for the first time,which were helpful to analyze the RSC converter performance regarding the loading effect and the variation of input voltage.A frequency control method for RSC converters was achieved based on the output voltage expression.A step-down RSC converter was used as an example to describe the equation derivation.The similar steady-state analysis could be applied to other types of ZCS RSC converters.Finally,experimental results on a 12V/5V/2.5A prototype are found to be nearly in accordance with the theoretical results.