In this paper, a series-capacitor-based interleaving buck power factor correction (PFC) converter is proposed, the intermediate energy storage capacitance of which is operated at discontinuous capacitor voltage mode (DCVM), and automatic power factor (PF) correction for this converter is obtained. Moreover, the voltage across the series capacitor of the proposed PFC converter is clamped at the input voltage, and thus peak voltage stress existed in the traditional DCVM buck PFC could be relieved. By effectively regulating the charge/discharge time for the series capacitor, ultrahigh step-down conversion ratio of the proposed converter is achieved, the conversion ratio of which is independent of the duty cycle and only related to the switching frequency and circuit parameters. Therefore, high PF can be obtained due to very narrow deadtime of the input current. Meanwhile, the proposed PFC converter can realize the soft turn-on of part power switch and soft turn-off of part power diodes. In addition, comparing with the traditional discontinuous inductor current mode PFC, the input current of the proposed PFC converter is continuous so that the peak value and root-mean-square value of input current can be reduced. The operational principle, performance analysis, and parameter design principle are given in this paper. The analysis results show that the PF and total harmonic distortion are also independent of the duty cycle. Finally, a 220-Vac input, 60 W/15 V output experimental prototype is built to verify the validity of the theoretical analysis.

中文翻译：

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具有高功率因数和超高降压转换比的串联电容器降压 PFC 转换器


本文提出了一种基于串联电容器的交错降压功率因数校正（PFC）转换器，其中间储能电容工作在不连续电容器电压模式（DCVM），并为此提供自动功率因数（PF）校正获得转换器。此外，所提出的 PFC 转换器串联电容器两端的电压被钳位在输入电压，因此可以缓解传统 DCVM 降压 PFC 中存在的峰值电压应力。通过有效调节串联电容器的充电/放电时间，实现了所提出的转换器的超高降压转换比，其转换比与占空比无关，仅与开关频率和电路参数有关。因此，由于输入电流的死区时间非常窄，可以获得高PF。同时，所提出的PFC变换器可以实现部分功率开关的软开通和部分功率二极管的软关断。此外，与传统的不连续电感电流模式PFC相比，所提出的PFC转换器的输入电流是连续的，因此可以降低输入电流的峰值和均方根值。本文给出了其工作原理、性能分析和参数设计原则。分析结果表明，PF 和总谐波失真也与占空比无关。最后搭建了220Vac输入、60W/15V输出的实验样机，验证了理论分析的有效性。