Buck型单开关整合式功率因数校正变换器

Buck-type Single-switch Integrated Power Factor Correction Converter

传统的Buck功率因数校正PFC(power factor correction)变换器存在谐波电流大的缺点,限制了其应用范围。提出并分析了一种Buck型单开关整合式功率因数校正变换器。该变换器由一个Buck PFC变换器和一个Buck-Boost PFC变换器通过一个开关管整合而成,简化了控制;同时,采用恒导通时间控制,消除了Buck PFC变换器输入电流的死区;结合Buck和Buck-Boost变换器的优势,在全输入电压范围下可以实现高功率因数和高效率。介绍并分析了该变换器的电路结构、工作原理、稳态特性以及设计思路,最后,搭建了一台56 W的实验样机,验证了分析结果的正确性。

The conventional Buck-type power factor correction(PFC)converter has a disadvantage of high harmonic current,which limits its applications.A Buck-type single-switch integrated PFC converter is proposed and analyzed.This converter is composed of a Buck-type PFC converter and a Buck-Boost PFC converter,and they are integrated by only one active switch,thereby simplifying the control.Under the constant on time(COT)control,the dead zone of input current in the Buck-type PFC converter is eliminated.With advantages of Buck and Buck-Boost converters,this converter can achieve a high power factor and a high efficiency in universal-input applications.The circuit structure,working principle,steady-state characteristics and design considerations of the proposed converter are introduced and analyzed.Finally,a 56 W prototype was built,and experimental results verified the analysis results.