高效临界模式SEPIC PFC电路设计

Research and Design of High Efficiency SEPIC PFC Circuit with Critical Discontinuous Current Mode

具有升降压功能的单级SEPIC PFC电路,工作在电流临界断续模式时,可降低功率器件的开关损耗和提高变换器的效率,此种电路在中小功率PFC变换场合得到广泛的应用。针对电流临界断续模式SEPIC PFC电路,分析电路主要特点和电路工作原理,提出基于L6561控制芯片的电流临界断续模式SEPIC PFC电路的设计原则和方法,此电路在升降压单级功率因数校正拓扑中具有结构简单、输入输出电压同相和控制简单等优点。在此基础上设计了1台80 W的实验样机,实验结果验证了设计方法的可行性和电路工作的有效性。

Single-stage SEPIC PFC circuit has buck-boost function.It can reduce the switching losses of power devices and improve the efficiency of the converter when working in the critical discontinuous current mode.And this circuit has been widely used in the small and medium power PFC transform occasions.The characteristics and principle of SEPIC PFC circuit was analyzed,and the design principle and method based on the L6561 was proposed.This circuit has the advantages of simple structure,the output voltage in the same phase with input voltage and control simple in the buck-boost single-stage power factor correction topology.On this basis,an experimental prototype rated power of 80 W is designed,and the experimental results verify the design feasibility and the effectiveness of the circuit work.