DCM-CRM Boost-Flyback单级PFC变换器

DCM-CRM Boost-Flyback single-stage PFC converter

为了实现功率因数校正(PFC)功能,单级Boost-Flyback变换器的前级Boost变换器通常工作在断续导电模式(DCM),为了实现高效率,通过控制使后级Flyback变换器工作在临界连续导电模式(CRM)。详细分析了变换器的工作原理和功率因数、中间储能电容电压、开关频率等相关工作特性,并搭建了60 W的实验样机,验证了此变换器能够仅使用1个开关管和1个峰值电流模控制器,同时实现PFC功能和恒定输出电压,且相比DCM-DCM,DCM-CRM Boost-Flyback单级PFC变换器在保持相同功率因数的前提下,提高了变换器的效率。

In order to realize PFC(Power Factor Correction)function,the pre-stage Boost converter of BoostFlyback single-stage converter usually works at DCM(Discontinuous Conduction Mode).In order to achieve high efficiency,the post-stage Flyback converter of Boost-Flyback single-stage converter is controlled to operate at CRM(CRitical continuous conduction Mode).The operation principle and operation characteristics of the converter including power factor,the voltage of link capacitor,switching frequency are analyzed in detail.A 60 W experimental prototype is built to verify that the PFC function and constant output voltage can be realized at the same time with only one switching transistor and one peak current mode controller.Compared with DCM-DCM operation mode,DCM-CRM Boost-Flyback single-stage PFC converter improves the efficiency with same power factor.