谐振开关电容DC/DC变换器拓扑研究综述

开关电容变换器(switchedcapacitorconverter,SCC)具有效率高、体积小、重量轻等优点,适用于数据中心、电动汽车等对效率和功率密度要求较高的场合。文章归纳出一个谐振开关电容基本单元,基于此,对现有谐振开关电容变换器的拓扑结构和软开关工作原理进行分析,并概括为串并联、多级模块化、多电平及级联等4种组成类型。文章总结移相、调频、占空比分配等调压方法,指出通过移相或改变开关频率,使变换器工作在零电压开关(zerovoltage switching,ZVS),可以实现电压连续调节;占空比重新分配,改变开关状态,可以实现电压断续调节。针对无源器件参数差异造成的开关管电压振荡问题,给出耦合电感去除法和电感共用法等解决方案,可省去相应的电压箝位电路。将用于实现高增益和多电平的开关电容单元应用于谐振SCC,并对其进行改进,可提升其电压变换比,便于电路参数选择,提高稳定性。最后,对典型谐振SCC进行性能对比,并提炼现存共性问题,供读者参考。

Review of Topological Research on Resonant Switched Capacitor DC/DC Converter

Switched capacitor converter(SCC) has the advantages of high efficiency, small size, light weight, etc., which makes it suitable for occasions with high efficiency and power density requirements such as data center and electric vehicle. In this paper, a basic unit of resonant switched capacitor was summarized, which was used to analyze the topology and soft-switching operating principle of existing resonant switched capacitor converters, and divided into four types of composition such as series-parallel, multi-stage modular, multi-level and cascade. This paper summarized the voltage regulation methods such as phase shift, frequency modulation, and duty cycle distribution. It was pointed out that the voltage can be continuously adjusted by shifting the phase or changing the switching frequency to make the converter work in zero voltage switching(ZVS). Redistribution of duty cycle to change the switch state can achieve intermittent voltage regulation. For the voltage oscillation problem of the switches caused by the difference of passive device parameters, the solutions of coupling inductance removal and common use of inductor were given in this article, which can save the corresponding voltage clamping circuits. This article applied the switched capacitor unit in the high-gain/multilevel converter to the resonant SCC, which can improve the voltage conversion rate. And on this basis, this article further improved the structure of the converter, which can facilitate parameter selection and improve its stability. Finally, this paper compared the performance of typical resonant SCCs and extracted three existing common problems for the reader’s reference.